Non-aqueous battery of a thin configuration

ABSTRACT

A non-aqueous battery is provided in a pouchy casing comprising opposing sheets of at least three-layer laminates, each laminate comprising (1) an inner thermoplastic resin layer, (2) a middle metal foil layer, and (3) an outer electrically insulating material layer, wherein the pouchy casing has an elongated, hermetic adhesion area along a periphery of the pouchy casing, and the middle metal foil layer has a peripheral elongated region in the elongated, hermetic adhesion area of the pouchy casing, and at least a pair of terminals electrically connected to the cathode and anode of the battery extends through and protrudes from the terminal-withdrawal sites in the elongated, hermetic adhesion area toward the outside of the pouchy casing, and the battery has at least one of the following features: (i) the peripheral elongated region of the middle metal foil layer has cut-out portions around the terminal-withdrawal sites and (ii) the surface of the peripheral edge of the pouchy casing is provided with electric insulation at least at portions around the terminal-withdrawal sites.

This application is the national phase 35 U.S.C. §371 of prior PCTInternational Application No. PCT/JP98/01193 which has an Internationalfiling date of Mar. 19, 1998 which designated the United States ofAmerica.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

The present invention relates to a novel non-aqueous battery of a thinconfiguration. More specifically, the present invention is concernedwith a non-aqueous battery of a thin configuration, comprising ahermetically sealed pouchy casing enveloping an electrochemical cell,and terminals electrically connected to a cathode and an anode of theelectrochemical cell, wherein the pouchy casing comprises oppositesheets of at least-three-layer laminates, each comprising an innerthermoplastic resin layer, a middle metal foil layer and an outerelectrically insulating material layer, and the pouchy casing has anelongated, hermetic adhesion area along a periphery of the pouchycasing, in which adhesion area the opposite inner thermoplastic resinlayers are melt-adhered to each other, thereby forming a hermetic sealof the pouchy casing, wherein the middle metal foil layer (2) has aperipheral elongated region in said elongated, hermetic adhesion area ofthe poaching casing, with the terminals extending through and protrudingfrom terminal-withdrawal sites in the elongated, hermetic adhesion areatoward the outside of the pouchy casing, and wherein the non-aqueousbattery satisfies at least one of the following characteristics (i) and(ii):

(i) the peripheral elongated region of the middle metal foil layer (2)has cut-out portions around the terminal-withdrawal sites in theelongated hermetic adhesion area of the pouchy casing through which theterminals extend wherein each of the cut-out portions in the peripheralelongated region of the middle metal foil layer in the elongated,hermetic adhesion area has a predetermined width-wise depth as viewedand measured in a direction of the width of the peripheral elongatedregion of the middle metal foil layer from a peripheral edge of a pouchycasing, and wherein portions of the peripheral elongated region of saidmiddle foil layer that are not cut out remain in the elongated hermeticadhesion area and the width of each of the remaining non-cut-outportions of the metal foil layer is at least ten times the thickness ofthe inner thermoplastic resin layer (1) in the elongated, hermeticadhesion area; and

(ii) the surface of the peripheral edge of the pouchy casing comprisedof the laminate is provided with electric insulation at least atportions thereof around the terminal-withdrawal sites.

By virtue of the above-mentioned unique structure, the non-aqueousbattery of the present invention having a thin configuration isadvantageous not only in that it is light in weight, thin and flexible,but also in that it has an excellent moisture resistance and anexcellent air tightness and is free from the danger of the occurrence ofa short-circuiting at portions around the terminal-withdrawal sites.Therefore, the non-aqueous battery of the present invention can beadvantageously used especially as a small, light-weight battery (forexample, as a battery for portable equipments) having a high capacityand excellent safety.

PRIOR ART

In accordance with the tendency of reduction in potential of lithium.Conventionally, as casings for such batteries, metallic containersprepared by shaping a metal sheet into the form of a cylinder, apolygon, a coin or the like in accordance with the use of the batteryhave been used. However, it is difficult to reduce the weight of such abattery having a metallic casing, and also there are limitations withrespect to the freedom of designing the shapes of metallic casings.

On the other hand, as compared to the above battery having a metalliccasing, not only does a battery having a casing prepared from a laminatecomprised mainly of a metal foil and a resin film become light in weightand flexible, but also the thickness of the battery can be easilyreduced. In addition, with respect to such a battery having a casingmade of a laminate comprised mainly of a metallic foil and a resin film,the sealing of the battery can be performed with ease during theproduction thereof. As examples of such batteries having laminate typecasings, Unexamined Japanese Patent Application Laid-Open SpecificationNos. 60-100362 and 1-112652 disclose non-aqueous primary batterieshaving laminate type casings, and Unexamined Japanese Patent ApplicationLaid-Open Specification No. 60-49568 and British Patent ApplicationPublication No. 2149197 disclose solid electrolyte batteries havinglaminate type casings. Each of the batteries disclosed in these priorart documents has a casing made of either a two-layer laminate comprisedof a metal foil layer and a thermoplastic resin layer or a three-layerlaminate comprised of an electrically insulating material layer, a metalfoil layer and a thermoplastic resin layer. In such batteries, anelectrochemical cell having terminals made of a SUS film or the like isenveloped by a pouchy casing prepared by a method in which theabove-mentioned laminate is folded so as for the thermoplastic resinlayers to be opposite to each other as inner layers, and the oppositeinner thermoplastic resin layers are melt-adhered to each other along aperiphery of the opposite inner thermoplastic resin layers to form ahermetic adhesion area, thereby hermetically sealing the pouchy casing,while positioning the terminals so that the terminals of the batteryextend through and protrude from the hermetic adhesion area toward theoutside of the pouchy casing.

In the conventional battery casings of a laminate type, the metal foillayer of the laminate serves to make the battery impervious topermeation of water vapor, and the electrically insulating materiallayer has an effect to protect the metal foil layer. The metal foillayer of the laminate used for the battery casing is made of aluminum orthe like; the thermoplastic resin layer of the laminate is made of anionomer, polyethylene, polypropylene or the like; and the electricallyinsulating material layer is made of polypropylene, polyethyleneterephthalate or the like. Conventionally, the use of such a laminatefor a battery casing has posed the following problems. Ashort-circuiting frequently occurs between the metal foil layer and theterminals during the melt-adhesion conducted for sealing the casing inthe production of the battery. Further, after the production of thebattery, a short-circuiting frequently occurs between the terminals andthe metal foil layer exposed in the peripheral edge of the casing. Theoccurrence of these short-circuitings are serious problems from theviewpoint of reliability and safety during the production and use of thebattery.

As a method for preventing the occurrence of a short-circuiting duringthe melt-adhesion for sealing the casing in the production of thebattery, Unexamined Japanese Patent Application Laid-Open SpecificationNo. 60-86754 and Examined Japanese Patent Application Publication No.4-58146 disclose a method in which an intermediate electricallyinsulating material layer capable of remaining intact during themelt-adhesion is interposed between the metal foil layer and thethermoplastic resin layer of the laminate. However, batteries producedby this method do not solve the problem that a short-circuiting islikely to occur between the terminals and the metal foil layer exposedin the peripheral edge of the casing. Moreover, this method is alsodisadvantageous in that, since the intermediate electrically insulatingmaterial layer employed in this method is intact during themelt-adhesion for sealing the casing, a good adhesion cannot be obtainedbetween the thermoplastic resin layer and the intermediate electricallyinsulating material layer, which results in a lowering of the airtightness and moisture resistance of the battery. Further, in thismethod, the production process becomes complicated.

There has been known a battery having a hermetically sealed pouchycasing made of a laminate of an inner thermoplastic structural adhesivelayer, a middle metal foil layer and an outer high heat resistantpolyester layer, in which the hermetic adhesion area is free of themetal foil layer, and the terminals extend through the elongatedhermetic adhesion area (see Unexamined Japanese Patent ApplicationLaid-Open Specification No. 3-62447 corresponding to European PatentApplication Publication No. 397 248). In this battery, the casing has aportion along the inner side of the hermetic adhesion area, whichportion has neither the hermetic adhesion area nor the metal foil layer.Therefore, when such battery is used, for example, as a secondarybattery which is required to be capable of stable operation for a longperiod of time, problems arise that the battery suffers an intrusion ofsubstances (such as water vapor) which impair battery performance, andalso suffers a leaking-out of the solvent molecules of the electrolyticliquid.

Further, Unexamined Japanese Patent Application Laid-Open SpecificationNo. 60-49568 discloses a method in which a battery is covered with athermosetting resin, followed by a heat-curing of the thermosettingresin. This method is effective for preventing a short-circuitingbetween the metal foil layer and the terminals, but the elevatedtemperature necessary for curing the thermosetting resin is likely toadversely affect the electrochemical cell of the battery.

SUMMARY OF THE INVENTION

In this situation, the present inventors have made extensive andintensive studies with a view toward solving the above difficultproblems accompanying the prior art, that is, toward developing anon-aqueous battery of a thin configuration, which comprises anon-aqueous electrochemical cell enveloped by a pouchy casing made bymelt-adhering opposite sheets of laminates and which has advantages notonly in that a short-circuiting between a metal foil layer and terminalscan be surely prevented, but also in that the battery can be easilyproduced and exhibits an excellent air tightness and an excellentmoisture resistance. As a result, it has unexpectedly been found thatthe above objective can be attained by a non-aqueous battery whichemploys a pouchy casing made of opposites sheets of at least-three-layerlaminates, each comprising an inner thermoplastic resin layer, a middlemetal foil layer and an outer electrically insulating material layer,wherein the pouchy casing has an elongated, hermetic adhesion area alonga periphery of the pouchy casing in which adhesion area the oppositeinner thermoplastic resin layers are melt-adhered to each other and thepouchy casing has terminal-withdrawal sites in the elongated, hermeticadhesion area, and wherein the pouchy casing satisfies at least one ofthe following characteristics (i) and (ii):

(i) the peripheral elongated region of the middle metal foil layer (2)has cut-out portions around the terminal-withdrawal sites in theelongated hermetic adhesion area of the pouchy casing through which theterminals extend wherein each of the cut-out portions in the peripheralelongated region of the middle metal foil layer in the elongated,hermetic adhesion area has a predetermined width-wise depth as viewedand measured in a direction of the width of the peripheral elongatedregion of the middle metal foil layer from a peripheral edge of a pouchycasing, and wherein portions of the peripheral elongated region of themiddle metal foil layer that are not cut out remain in the elongatedhermetic adhesion area and the width of each of the remainingnon-cut-out portions of the metal foil layer is at least ten times thethickness of the inner thermoplastic resin layer (1) in the elongated,hermetic adhesion area; and

(ii) the surface of the peripheral edge of the pouchy casing comprisedof the laminate is provided with electric insulation at least atportions thereof around the terminal-withdrawal sites.

That is, it has been found that, by the use of the above pouchy casingin a non-aqueous battery, not only can the occurrence of ashort-circuiting be very greatly suppressed, but also theelectrochemical cell can be easily sealed inside the casing whileachieving an excellent air tightness and an excellent moistureresistance. The present invention has been made, based on this novelfinding.

Therefore, a primary object of the present invention is to provide anon-aqueous battery of a lightweight and a thin configuration, which isfree from the danger of the occurrence of a short-circuiting andexhibits an excellent air tightness, a high reliability and a highsafety.

The foregoing and other objects, features and advantages of the presentinvention will be apparent from the following detailed description takenin connection with the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 shows schematic views explaining the non-aqueous battery of athin configuration prepared in Example 1, wherein FIG. 1(a) is a planview of a laminate (used for preparing a pouchy casing) in which amiddle metal foil layer is partly cut-out at several portions in oneside thereof; FIG. 1(b) is a cross-sectional view taken along line Ib—Ibof FIG. 1(a); and FIG. 1(c) is a plan view of the non-aqueous battery ofa thin configuration;

FIG. 2 shows schematic views explaining the non-aqueous battery of athin configuration prepared in Example 2, wherein FIG. 2(a) is a planview of a laminate (used for preparing a pouchy casing) in which amiddle metal foil layer is cut-out along the entire length of one sidethereof; FIG. 2(b) is a cross-sectional view taken along line IIb—IIb ofFIG. 2(a); and FIG. 2(c) is a plan view of the non-aqueous battery of athin configuration;

FIG. 3 shows schematic views explaining the non-aqueous battery of athin configuration prepared in Example 3, wherein FIG. 3(a) is a planview of a laminate (used for preparing a pouchy casing) in which theentire periphery of a middle metal foil layer is cut-out, wherein theentire periphery includes both the side having portions corresponding toterminal-withdrawal sites and the side opposite thereto; FIG. 3(b) is across-sectional view taken along line IIIb—IIIb of FIG. 3(a); and FIG.3(c) is a plan view of the non-aqueous battery of a thin configuration;and

FIG. 4 shows schematic views explaining the non-aqueous battery preparedin Example 6, wherein FIG. 4(a) is a partly-cut-away plan view of thenon-aqueous battery (terminals 9, 9 are shown by imaginary lines), inwhich the surface of the peripheral edge of the casing is provided withelectric insulation at portions thereof around the terminal-withdrawalsites; and FIG. 4(b) is a cross-sectional view taken along line IVb—IVbof FIG. 4(a).

DESCRIPTION OF REFERENCE NUMERALS

1: Inner thermoplastic resin layer

2: Middle metal foil layer

3: Outer electrically insulating material layer

4: Elongated, hermetic adhesion area

5: Terminal-withdrawal site

6: Cut-out portion of a middle metal foil layer

7: Electrically insulating material

9: Terminal

10: Laminate

20: Casing

30: Non-aqueous battery of a thin configuration

]1, ]2, ]3: Line about which a laminate is folded in two for producing acasing

DESCRIPTION OF THE INVENTION

According to the present invention, there is provided a non-aqueousbattery of a thin configuration, comprising:

(a) an electrochemical cell comprising a cathode, an anode and anon-aqueous electrolyte interposed between the cathode and the anode,

(b) a hermetically sealed pouchy casing enveloping the electrochemicalcell (a), and

(c) at least a pair of terminals electrically connected to the cathodeand the anode,

the pouchy casing comprising opposite sheets of at least-three-layerlaminates, each comprising (1) an inner thermoplastic resin layer, (2) amiddle metal foil layer and (3) an outer electrically insulatingmaterial layer, wherein the pouchy casing has an elongated, hermeticadhesion area along a periphery of the pouchy casing, in which adhesionarea the opposite inner thermoplastic resin layers (1) are melt-adheredto each other, thereby forming a hermetic seal of the pouchy casing,

the terminals extending through and protruding from terminal-withdrawalsites in the elongated, hermetic adhesion area toward the outside of thepouchy casing,

wherein the non-aqueous battery satisfies at least one of the followingcharacteristics (i) and (ii):

(i) the peripheral elongated region of the middle metal foil layer (2)has cut-out portions around the terminal-withdrawal sites in theelongated hermetic adhesion area of the pouchy casing through which theterminals extend, wherein each of the cut-out portions in the peripheralelongated region of the middle metal foil layer in the elongated,hermetic adhesion area has a predetermined width-wise depth as viewedand measured in a direction of the width of the peripheral elongatedregion of the middle metal foil layer from a peripheral edge of a pouchycasing, and wherein portions of the peripheral elongated region of themiddle metal foil layer that are not cut-out remain in the elongatedhermetic adhesion area and the width of each of the remainingnon-cut-out portions of the metal foil layer is at least ten times thethickness of the inner thermoplastic resin layer (1) in the elongated,hermetic adhesion area; and

(ii) the surface of the peripheral edge of the pouchy casing comprisedof the laminate is provided with electric insulation at least atportions thereof around the terminal-withdrawal sites.

For an easy understanding of the present invention, the essentialfeatures and various preferred embodiments of the present invention areenumerated below.

1. A non-aqueous battery of a thin configuration, comprising:

(a) an electrochemical cell comprising a cathode, an anode and anon-aqueous electrolyte interposed between the cathode and the anode,

(b) a hermetically sealed pouchy casing enveloping the electrochemicalcell (a), and

(c) at least a pair of terminals electrically connected to the cathodeand the anode,

the pouchy casing comprising opposite sheets of at least-three-layerlaminates, each comprising (1) an inner thermoplastic resin layer, (2) amiddle metal foil layer and (3) an outer electrically insulatingmaterial layer, wherein the pouchy casing has an elongated, hermeticadhesion area along a periphery of the pouchy casing, in which adhesionarea the opposite inner thermoplastic resin layers (1) are melt-adheredto each other, thereby forming a hermetic seal of the pouchy casing,wherein the middle metal foil layer (2) has a peripheral elongatedregion in the elongated, hermetic adhesion area of the pouchy casing,with the terminals extending through and protruding fromterminal-withdrawal sites in the elongated, hermetic adhesion areatoward the outside of the pouchy casing,

wherein the non-aqueous battery satisfies at least one of the followingcharacteristics (i) and (ii):

(i) the peripheral elongated region of the middle metal foil layer (2)has cut-out portions around the terminal-withdrawal sites in theelongated hermetic adhesion area of the pouchy casing through which theterminals extend wherein each of the cut-out portions in the peripheralelongated region of the middle metal foil layer in the elongated,hermetic adhesion area has a predetermined width-wise depth as viewedand measured in a direction of the width of the peripheral elongatedregion of the middle metal foil layer from a peripheral edge of a pouchycasing, and wherein portions of the peripheral elongated region of themiddle metal foil layer that are not cut-out remain in the elongatedhermetic adhesion area and the width of each of the remainingnon-cut-out portions of the metal foil layer is at least ten times thethickness of the inner thermoplastic resin layer (1) in the elongated,hermetic adhesion area; and

(ii) the surface of the peripheral edge of the pouchy casing comprisedof the laminate is provided with electric insulation at least atportions thereof around the terminal-withdrawal sites.

2. The battery according to item 1 above, wherein the width of theelongated, hermetic adhesion area is within the range of from 1 to 50mm.

3. The battery according to item 1 or 2 above, wherein the depth of eachof the cut-out portions of the middle metal foil layer is 0.1 mm or moreand is not more than 80% of the width of the elongated, hermeticadhesion area.

4. The battery according to item 3 above, wherein the depth of each ofthe cut-out portions of the middle metal foil layer is 0.5 mm or moreand is not more than 50% of the width of the elongated, hermeticadhesion area.

5. The battery according to any one of items 1 to 4 above, wherein thewidth of the cut-out portion of the middle metal foil layer is not lessthan a half of the circumference of the cross-section of a portion ofthe terminal which is positioned at the terminal-withdrawal site.

6. The battery according to any one of items 1 to 5 above, wherein themelting temperature of the outer electrically insulating material layer(3) is 260° C. or more.

7. The battery according to any one of items 1 to 6 above, wherein theouter electrically insulating material layer (3) has at least onemodulus value selected from the group consisting of a tension modulus of300 kg/mm² or more and a compression modulus of 50 kg/mm² or more.

8. The battery according to any one of items 1 to 7 above, wherein thelaminate further comprises at least one intermediate electricallyinsulating material layer between the inner thermoplastic resin layer(1) and the middle metal foil layer (2).

9. The battery according to item 8 above, wherein the meltingtemperature of the intermediate electrically insulating material layerdisposed between the inner thermoplastic resin layer (1) and the middlemetal foil layer (2) is 260° C. or more.

10. The battery according to item 8 or 9 above, wherein the intermediateelectrically insulating material layer disposed between the innerthermoplastic resin layer (1) and the middle metal foil layer (2) has atleast one modulus value selected from the group consisting of a tensionmodulus of 300 kg/mm² or more and a compression modulus of 50 kg/mm² ormore.

11. The battery according to any one of items 1 to 10 above, wherein atleast one layer selected from the group consisting of the thermoplasticresin layer and the electrically insulating material layer is made of apolyvinylidene chloride resin.

12. The battery according to any one of items 1 to 11 above, wherein theterminal is made of aluminum or copper.

13. The battery according to item 12 above, wherein at least a part ofthe surface of the terminal is roughened.

14. The battery according to any one of items 1 to 13 above, whichfurther comprises means adapted to be actuated to cut at least a part ofthe terminal when the pouchy casing. suffers expansion and distortion.

15. The battery according to any one of items 1 to 14 above, wherein thebattery is a secondary lithium ion battery.

As mentioned above, the non-aqueous battery of the present inventionhaving a thin configuration is a battery comprising (a) anelectrochemical cell comprising a cathode, an anode and a non-aqueouselectrolyte interposed between the cathode and the anode, (b) ahermetically sealed pouchy casing enveloping the electrochemical cell(a), and (c) at least a pair of terminals electrically connected to thecathode and the anode. The pouchy casing comprises opposite sheets of atleast-three-layer laminates, each comprising (1) an inner thermoplasticresin layer, (2) a middle metal foil layer and (3) an outer electricallyinsulating material layer. The pouchy casing has an elongated, hermeticadhesion area along a periphery of the pouchy casing, in which adhesionarea the opposite inner thermoplastic resin layers (1) are melt-adheredto each other, thereby forming a hermetic seal of the pouchy casingwherein the middle metal foil layer (2) has a peripheral elongatedregion in the elongated, hermetic adhesion area of the pouchy casing.The terminals extend through and protrude from terminal-withdrawal sitesin the elongated, hermetic adhesion area toward the outside of thepouchy casing. Further, the non-aqueous battery of the present inventionhaving a thin configuration satisfies at least one of the followingcharacteristics (i) and (ii):

(i) the peripheral elongated region of the middle metal foil layer (2)has cut-out portions around the terminal-withdrawal sites in theelongated hermetic adhesion area of the pouchy casing through which theterminals extend wherein each of the cut-out portions in the peripheralelongated region of the middle metal foil layer in the elongated,hermetic adhesion area has a predetermined width-wise depth as viewedand measured in a direction of the width of the peripheral elongatedregion of the middle foil layer from a peripheral edge of a pouchycasing, and wherein portions of the peripheral elongated region of themiddle metal foil layer that are not cut-out remain in the elongatedhermetic adhesion area and the width of each of the remainingnon-cut-out portions of the metal foil layer is at least ten times thethickness of the inner thermoplastic resin layer (1) in the elongated,hermetic adhesion area; and

(ii) the surface of the peripheral edge of the pouchy casing comprisedof the laminate is provided with electric insulation at least atportions thereof around the terminal-withdrawal sites.

As mentioned above, the pouchy casing (b) used in the present inventioncomprises opposite sheets of at least-three-layer laminates, eachcomprising (1) an inner thermoplastic resin layer, (2) a middle metalfoil layer and (3) an outer electrically insulating material layer.

In the elongated, hermetic adhesion area of the pouchy casing, theopposite inner thermoplastic resin layers (1) (which constitute theinside surfaces of the casing) are melt-adhered to each other along aperiphery of the casing, thereby forming a hermetic seal of the pouchycasing so as to seal up the electrochemical cell therein. Thus, thepouchy casing isolates the electrochemical cell from the outside,thereby making the battery impervious not only to a contamination withforeign matters (such as water vapor), but also to a leaking-out of theelectrolytic liquid used in the electrochemical cell. Therefore, thethermoplastic resin used for the inner thermoplastic resin layer (1) ispreferably one which is neither soluble in nor swellable with theelectrolytic liquid used in the electrochemical cell. Examples of suchthermoplastic resins include polyethylene, polypropylene, polystyrene,polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, polyvinylchloride, polyamide, polyester, a polyester copolymer, polyvinylidenechloride, polycarbonate, polyphenylene oxide, formalized polyvinylalcohol, acrylic acid-modified polyethylene and acrylic acid-modifiedpolypropylene. Further, for improving the adhesion between the oppositeinner thermoplastic resin layers, and for improving the adhesion of theinner thermoplastic resin layers to the terminals, an oxidationtreatment or a coating may be performed with respect to the surface ofthe inner thermoplastic resin layer (1). It is preferred that thethickness of the inner thermoplastic resin layer (1) is selected, takinginto consideration the balance between the desired strength of layer (1)during the melt-adhesion and the desired weight reduction of thebattery. Specifically, the thickness of the inner thermoplastic resinlayer (1) is preferably in the range of from 10 to 100 μm, morepreferably from 20 to 90 μm, and most preferably from 30 to 80 μm.

It is preferred that the metal foil layer (2) of the pouchy casingserves to make the battery impervious not only to an intrusion of air,oxygen, nitrogen, water and other contaminants which may be presentaround the battery, but also to a leaking-out of the electrolyticliquid, so that a lowering of the battery performance can be suppressed.Examples of metals used for the middle metal foil layer (2) includealuminum, an aluminum alloy, a SUS, nickel and copper. From theviewpoint of achieving an excellent corrosion resistance, aluminum, analuminum alloy and a SUS are preferred. Aluminum and an aluminum alloy,which are light in weight and easily processable, are more preferred.The surface of the middle metal foil layer (2) may be roughened so as toincrease a strength of adhesion of the metal foil layer to other layersof the laminate.

It is preferred that the thickness of the middle metal foil layer (2) isselected, taking into consideration the balance between the desiredmoisture resistance, the desired weight reduction and the desiredprocessability. Specifically, the thickness of the middle metal foillayer (2) is preferably in the range of from 3 to 80 μm, more preferablyfrom 5 to 50 μm, most preferably from 7 to 30 μm.

The outer electrically insulating material layer (3), which constitutesthe outer surface of the pouchy casing, protects the middle metal foillayer (2) from an impact, a piercing and chemicals, which are likely tobe experienced by the outer surface of the casing. The outerelectrically insulating material layer (3) also serves to electricallyinsulate the middle metal foil layer (2) from other metallic materials,such as terminals, thereby preventing an inadvertent short-circuiting.It is necessary that the material used for the outer electricallyinsulating material layer (3) have a melting temperature higher thanthat of the inner thermoplastic resin layer (1) of the laminate so thatthe outer electrically insulating material layer (3) can remain intactduring the melt-adhesion. Examples of resins which can be used for theouter electrically insulating material layer (3) include a polyamideresin, a polyester resin, polyvinylidene chloride, polycarbonate,polyphenylene oxide, a glass fiber-containing nylon, cellophane,polyvinyl alcohol, polyimide, polyether imide, aromatic polyamide,polyphenylene sulfide, polyether sulfone, poly-para-xylene,polyetheretherketone, syndiotactic polystyrene, a liquid crystalpolymer, a fluororesin and a phenolic resin. If desired, a thermoplasticresin or a thermosetting resin having a melting temperature higher thanthat of the inner thermoplastic resin layer (1) of the laminate can beused in combination with above-mentioned resins.

It is preferred that the thickness of the outer electrically insulatingmaterial layer (3) is selected, taking into consideration the balancebetween the desired mechanical strength and the desired weightreduction. Specifically, the thickness of the outer electricallyinsulating material layer (3) is preferably in the range of from 1 to100 μm, more preferably from 2 to 80 μm, most preferably from 4 to 50μm.

As examples of methods for preparing the laminate, there can bementioned wet lamination, extrusion coating, coextrusion lamination, drylamination, hot-melt lamination, heat lamination and the like. Specificexamples of processes for realizing the above-mentioned laminationmethods include a process in which layers are laminated and subjected tomelt-adhesion by heat lamination; a process in which a film of amaterial having a low melting temperature, such as polyethylene,polypropylene or the like, is interposed between layers; a process inwhich an adhesive, such as a moisture-curing type urethane polyether, amoisture-curing type urethane polyester, urethane polyether, urethanepolyester, polyester polyol, polyisocyanate, or a hot-melt adhesive isinterposed between layers; a process in which a molten polymer is castedor extruded on a substrate to form a film; and a process in which apolymer solution or a polymer precursor in a liquid state is casted on asubstrate to form a film. The method for producing the laminate can beselected in accordance with the materials for the layers to belaminated. It is preferred that the laminate used for producing thepouchy casing is prepared, taking into consideration the moisturebarrier property necessary for a battery casing, the adhesion of thelaminate to the terminals, and the method used for sealing the pouchycasing.

As examples of methods for forming the hermetic adhesion area of thepouchy casing, there can be mentioned an impulse sealing; a sealingmethod using frictional heat, such as spin welding; a sealing methodusing external heating, such as heat sealing, a laser sealing, aninfrared radiation sealing and a hot jet sealing; and a sealing methodusing internal heating, such as radiofrequency sealing and ultrasonicsealing. In the elongated, hermetic adhesion area of the pouchy casing,the opposite inner thermoplastic resin layers (1) (which constitute theinner surfaces of the casing) are melt-adhered to each other along aperiphery of the pouchy casing so as to seal up the electrochemical cellinside the casing.

For increasing the adhesion strength in the battery of the presentinvention, hot-melt adhesives, such as a polyvinyl alcohol adhesive, anolefin adhesive, a rubber adhesive and a polyamide adhesive may beinterposed between the inner thermoplastic resin layer (1) and theterminals, or between the opposite sheets of the inner thermoplasticresin layers (1). It is preferred that the width of the elongated,hermetic adhesion area is selected, taking into consideration thebalance between the desired reliability of the hermetic seal and thedesired volume energy density of the battery. Specifically, forexhibiting the excellent effects of the present invention, the width ofthe hermetic adhesion area is preferably in the range of from 1 to 50mm, more preferably from 2 to 30 mm, most preferably from 2 to 20 mm, asmeasured from the peripheral edge of the casing.

The projection area of the battery may be reduced by folding thehermetic adhesion area so as to turn the peripheral edge of the casingtoward the middle portion of the battery. In this case, the width of thehermetic adhesion area is defined as a value as measured before thefolding.

The non-aqueous battery of the present invention having a thinconfiguration is provided with means for preventing a short-circuitingbetween the terminals (which extend through and protrude from theterminal-withdrawal sites of the pouchy casing) and a peripheral edge ofthe middle metal foil layer.

Specifically, such a short-circuiting can be effectively prevented bysatisfying at least one of the following characteristics (i) and (ii):

(i) the peripheral elongated region of the middle metal foil layer (2)has cut-out portions around the terminal-withdrawal sites in theelongated hermetic adhesion area of the pouchy casing, through which theterminals extend, wherein each of the cut-out portions in the peripheralelongated region of said middle metal foil layer in the elongated,hermetic adhesion area has a predetermined width-wise depth as viewedand measured in a direction of the width of the peripheral elongatedregion of the middle foil layer from a peripheral edge of a pouchycasing, and wherein portions of the peripheral elongated region of themiddle metal foil layer that are not cut-out remain in the elongatedhermetic adhesion area and the width of each of the remainingnon-cut-out portions of the metal foil layer is at least ten times thethickness of the inner thermoplastic resin layer (1) in the elongated,hermetic adhesion area; and

(ii) the surface of the peripheral edge of the pouchy casing comprisedof the laminate is provided with electric insulation at least atportions thereof around the terminal-withdrawal sites.

As mentioned above, in characteristic (i) defined in the presentinvention, the width of the middle metal foil layer in the elongated,hermetic adhesion area is at least ten times the thickness of the innerthermoplastic resin layer in the elongated, hermetic adhesion area. Thereason for this is as follows. In general, the moisture permeability ofa metal foil is less than {fraction (1/10)} of that of a resin film.When the width of the middle metal foil layer in the elongated, hermeticadhesion area is ten times or more the thickness of the innerthermoplastic resin layer in the elongated, hermetic adhesion area, themoisture permeability through the peripheral edge surface of the middlemetal foil layer in the widthwise direction of the middle metal foillayer becomes far smaller than the moisture permeability of the pouchycasing in the thicknesswise direction, so that the moisture permeabilitythrough the peripheral edge surface of the pouchy casing becomes assmall as negligible, as compared to the moisture permeability of thepouchy casing in the thicknesswise direction.

For preventing a short-circuiting between the terminals and theperipheral edge of the middle metal foil layer (2), the width of themiddle metal foil layer (2) in the elongated, hermetic adhesion areamust be less than the width of the elongated, hermetic adhesion area atleast at portions of layer (2) around the terminal-withdrawal sites.Therefore, the width of the middle metal foil layer (2) in theelongated, hermetic adhesion area is preferably at least ten times, morepreferably at least 20 times, most preferably at least 40 times thethickness of the inner thermoplastic resin layer in the elongated,hermetic adhesion area, with the proviso that the above-mentioned widthis less than the width of the elongated, hermetic adhesion area.

At least at portions around the terminal-withdrawal sites, the elongatedportion of the middle metal foil layer (2) in the hermetic adhesion areais cut-out in a peripheral portion thereof by a predetermined width-wisedepth which is sufficient to maintain a good insulation between theterminals and the peripheral edge of the middle metal foil layer. It ispreferred that the depth of the cut-out portion of the middle metal foillayer is 0.1 mm or more and is not more than 80% of the width of theelongated, hermetic adhesion area. The reason why the preferred value ofthe width-wise depth of the cut-out portion of the metal foil layer (2)is 0.1 mm or more is as follows. In general, the total thickness of theinner thermoplastic resin layer (1) and the outer electricallyinsulating material layer (3) is approximately 0.1 mm. Therefore, forsurely covering the peripheral edge of the middle metal foil layer (2)by the peripheral areas of the layers (1) and (3) in the peripheral edgeof the pouchy casing, it is desired that a portion between theperipheral areas of the layers (1) and (3) is free of the middle metalfoil layer (2) over 0.1 mm or more as measured from the peripheral edgesof the layers (1) and (3). The reason why the preferred value of thedepth of the cut-out portion of the middle metal foil layer (2) is notmore than 80% of the width of the elongated, hermetic adhesion area isbecause, for obtaining a satisfactory level of moisture resistance, thedepth of the cut-out portion of the layer (2) need not be more than 80%of the width of the elongated, hermetic adhesion area. Therefore, fromthe viewpoint of exhibiting the excellent effects of the presentinvention, i.e., the effects that not only can a short-circuitingbetween the terminals and the middle metal foil layer be prevented, butalso a good moisture resistance can be obtained, it is preferred thatthe depth of the cut-out portion of the middle metal foil layer is 0.1mm or more (more advantageously 0.3 mm or more, most advantageously 0.5mm or more) and is not more than 80% (more advantageously not more than70%, most advantageously not more than 50%) of the width of theelongated, hermetic adhesion area.

It is preferred that the width of the cut-out portion of the middlemetal foil layer (2) is not less than a half of the circumference of thecross-section of a portion of the terminal which is positioned at theterminal-withdrawal site (i.e., preferably not less than the total ofthe thickness and the width of the terminal when the terminal is arectangular strip). It is more preferred that the width of the cut-outportion of the middle metal foil layer (2) is not less than 1.5 times ahalf of the circumference of the cross-section of a portion of theterminal which is positioned at the terminal-withdrawal site. It is mostpreferred that the width of the cut-out portion of the middle metal foillayer (2) is the same as the length of the side of the casing which sidehas the terminal withdrawal sites. The reason why the preferred value ofthe width of the cut-out portion of the middle metal foil layer (2) isnot less than a half of the circumference of the cross-section of aportion of the terminal which is positioned at the terminal withdrawalsite (i.e., not less than the total of the thickness and the width ofthe terminal when the terminal is a rectangular strip) is because thispreferred value of the cut-out portion is effective for surelypreventing a terminal from contacting the middle metal foil layer (2) atthe peripheral edge of the pouchy casing even when the terminal is bent.

The depth and width of the cut-out portion of the middle metal foillayer can be easily measured either using a scale graduated in 1millimeters or under an optical microscope using an objective micrometergraduated in 0.01 millimeters.

Examples of methods for forming the cut-out portion of the middle metalfoil layer (2) include a method in which the at least-three-layerlaminate is obtained in a state wherein the middle metal foil layer (2)has a cut-out portion, and a method in which an at least-three-layerlaminate wherein the middle metal foil layer (2) has no cut-out portionis produced and, then, the middle metal foil layer (2) exposed in theperipheral edge of the laminate is subjected to etching at a portionwhere a portion should be cut-out, thereby forming a cut-out portion byetching. Examples of methods in which the at least-three-layer laminateis obtained in a state wherein the middle metal foil layer (2) has acut-out portion include a method in which the layer (2) of the laminateis formed using a metal foil having a size smaller than the size of aresin film used for forming the layer (1) so that the layer (1) iscaused to have at least one peripheral portion free of the middle metalfoil layer (2), and a method in which the layer (2) of the laminate isformed using a patterning technique. Examples of methods in which thelayer (2) of the laminate is formed using a patterning technique includea method in which a mask capable of transmitting a pattern desired forthe layer (2) is provided on a resin film used for forming the layer (1)and, then, the middle metal foil layer (2) is formed on the layer (1) byvapor deposition through the mask; a method in which a substrate ispatterned using a solvent-soluble substance so as to form asolvent-soluble pattern corresponding to a cut-out portion, and themiddle metal foil layer (2) is formed on the substrate having thesolvent-soluble pattern thereon, and then, the solvent-soluble patternis removed by a solvent therefor together with a portion of the layer(2) formed on the pattern; and a method in which the middle metal foillayer (2) is formed on a substrate, and a resist layer having a patterndesired for the layer (2) is formed on the layer (2), and then, thelayer (2) is subjected to etching, thereby removing a portion of thelayer (2) having no resist layer.

In characteristic (ii) defined in the present invention, the surface ofthe peripheral edge of the pouchy casing is provided with electricinsulation at least at portions thereof around the terminal-withdrawalsites. By this characteristic (ii), the problem that a short-circuitingbetween a terminal and the middle metal foil layer is likely to occurwhen the terminal is bent at the peripheral edge of the pouchy casingcan be easily prevented.

With respect to the electric insulation treatment in characteristic(ii), it is preferred that the treatment is performed so that thesurface resistivity of the treated portion becomes 10⁶ Ω/□ or more, moreadvantageously 10⁷ Ω/□ or more.

It is preferred that the electric insulation treatment is performed sothat the electric insulation is achieved not only at the peripheral edgeof the casing at the terminal-withdrawal sites of the casing but also atportions contiguously extending around the terminal-withdrawal sites ofthe casing. It is preferred that the electric insulation treatment inthe widthwise direction of the terminal is performed so that the widthof the electrically insulated portion exceeds the width of the terminal.It is more preferred that the width of the electrically insulatedportion is at least 1.1 times the width of the terminal, mostadvantageously at least 1.2 times the width of the terminal. Further, itis preferred that the peripheral portions of both the front and backsurfaces of the pouchy casing, or the peripheral portions of both thefront and back surfaces of each of the opposite sheets of the laminatesused for producing the pouchy casing, are treated for electricinsulation so as to form an electrically insulated portion contiguouslycovering the peripheral portions of both surfaces of the pouchy casingover a predetermined depth from the peripheral edge of the pouchy casingaround the terminal-withdrawal sites thereof.

Examples of methods for performing the electric insulation treatmentinclude a method in which a tape, a film or a sheet of an insulatingmaterial is cut into a predetermined size and adhered to a predeterminedportion of the casing by means of an adhesive; a method in which aninsulating tape having an adhesive applied onto the back surface thereofis cut into a predetermined size and adhered to a predetermined portionof the casing through the adhesive; a method in which an insulating filmcapable of melt-adhesion is cut out into a predetermined size andmelt-adhered to a predetermined portion of the casing; and a method inwhich a predetermined portion of the casing is coated with an insulatingmaterial. Alternatively, the electric insulation treatment may also beperformed by a method in which a predetermined portion of the casing iscoated with a solution obtained by dissolving in an appropriate solventa resin having an insulating property, such as polyethylene.

Examples of insulating materials include inorganic solids, such as glassand mica; semisynthetic polymers, such as pulp and a cellulosederivative; thermoplastic resins, such as polyethylene, polyethyleneterephthalate and a fluororesin; and thermosetting resins, such as anepoxy resin, a polyamide resin and a polyimide resin.

Examples of insulating tapes having an adhesive applied onto the backsurface thereof include an adhesive-coated polyvinyl chloride tape, anadhesive-coated polyester tape, an adhesive-coated polyamide tape, anadhesive-coated silicone tape, an adhesive-coatedpolytetrafluoroethylene (trade name: Teflon) tape and an adhesive-coatedpaper tape.

Examples of insulating films and insulating sheets include a mica paper,a poly(p-phenyleneterephthalamide (trade name: Aramid)/mica paper,poly(p-phenyleneterephthalamide (trade name: Aramid) paper, a polyimidefilm, a nylon film, a polyethylene terephthalate film, apolytetrafluoroethylene (trade name: Teflon) sheet and a cellophane. Asexamples of adhesives used for adhering these films or sheets to thepouchy casing, there can be mentioned shellac, a synthetic resinadhesive, such as a phenol resin or an epoxy resin, a phthalic acidresin, a silicone resin, a polyester imide resin and a polyimide resin.

Examples of films capable of melt-adhesion include a polyethylene film,a polypropylene film and a polyethylene terephthalate/polyethylenelaminate film. These films can be melt-adhered to the casing.

Examples of coating materials for insulation include a polyimide coatingmaterial, a polyurethane coating material and an unsaturated polyestercoating material, such as a polyimide varnish, a polyester varnish, apolyester imide varnish and a polyamide imide varnish. With respect tothe method for applying a coating material to the casing, there can bementioned a method in which a coating material is applied to the casing,for example, by a brush or the like, and a method in which a portion ofthe casing to be coated is immersed into a coating material. Afterapplying the coating material to the casing, the applied coating issubjected to drying at an elevated temperature or room temperature,thereby allowing the solvent contained therein to volatilize.

The electric insulation treatment can be performed either before orafter the melt-adhesion of the opposite sheets of the laminates. When itis desired to perform the electric insulation treatment before themelt-adhesion, the operation is conducted as follows. First, theelectric insulation treatment by any one of the above-mentioned methodsis performed with respect to portions of the opposite sheets of thelaminates which portions correspond to the terminal-withdrawal sites ofthe casing to be prepared. Next, an electrochemical cell (comprising acathode, an anode and, interposed therebetween, a separator or a solidelectrolyte) having terminals is sandwiched between the above-mentionedopposite sheets of the laminates, and the terminals are positioned sothat the terminals protrude outwardly from between the opposite sheetsat positions corresponding to the portions treated for electricinsulation (which portions correspond to the terminal-withdrawal sitesof the casing to be prepared). Then, the opposite sheets of thelaminates are melt-adhered to each other along a periphery of theopposite sheets, thereby forming a battery of a thin configuration,which comprises a hermetically sealed pouchy casing enveloping theelectrochemical cell.

When the electric insulation treatment is performed after themelt-adhesion of the opposite sheets of the laminates, it is preferredthat the melt-adhesion is performed so that, at least at theterminal-withdrawal sites and portions around the terminal-withdrawalsites, the outer side of the elongated, hermetic adhesion area ispositioned slightly inside of the peripheral edge of the casing so as toleave small non-melt-adhered portions in the peripheral edge of thecasing. The reason for this is because, with respect to a casing havingsuch non-melt-adhered portions in the peripheral edge of the casing, theelectric insulation treatment can be easily performed, as compared tothe electric insulation treatment performed on a casing having no suchnon-melt-adhered portions in the peripheral edge of the casing.

In addition to the electric insulation treatment of the casing, aboundary between a terminal and the surface of the peripheral edge ofthe casing may also be treated for electric insulation. By treating theabove-mentioned boundary for electric insulation, a direct contactbetween the terminal and the surface of the peripheral edge of thecasing can be more surely prevented, so that the occurrence of ashort-circuiting can be more surely prevented between the terminal and aperipheral edge of the middle metal foil layer even when the terminal isbent at the peripheral edge of the casing.

The laminate used for producing the pouchy casing comprises the innerthermoplastic resin layer (1) (which constitutes the inner surface ofthe casing), the outer electrically insulating material layer (3) (whichconstitutes the outer surface of the casing), and the middle metal foillayer (2) which is disposed between the layers (1) and (3). It ispreferred that the laminate further comprises at least one intermediateelectrically insulating material layer between the inner thermoplasticresin layer (1) and the middle metal foil layer (2). It is desired thatthe optional intermediate electrically insulating material layerdisposed between the layers (1) and (2) has a high modulus. Theadvantage of the intermediate electrically insulating material layeroptionally disposed between the inner thermoplastic resin layer (1) andthe middle metal foil layer (2) is as follows. When the opposite sheetsof the laminates are melt-adhered to each other, it is possible thatvery small projections or uneven portions in the surfaces of theterminals pierce through the inner thermoplastic resin layer and contactwith the middle metal foil layer, thereby causing a short-circuitingbetween the cathode terminal and the anode terminal through the middlemetal foil layer. The intermediate electrically insulating materiallayer optionally disposed between the inner thermoplastic resin layer(1) and the middle metal foil layer (2) is effective for preventing theoccurrence of such a short-circuiting between the cathode and anodeterminals through the middle metal foil layer during the melt-adhesion.When a battery having a short-circuiting circuiting is subjected tocharging, electric voltage cannot be increased. Further, when a chargedbattery suffers a short-circuiting due to an impact or the like, a heatgeneration disadvantageously occurs in the battery.

With respect to the material used for the intermediate electricallyinsulating material layer (and also for the outer electricallyinsulating material layer), from the viewpoint of preventing the dangerthat projections in the surfaces of the terminals pierce through theinner thermoplastic resin layer and damage the inside of the casing, itis desired that the material has a melting temperature of 260° C. ormore, and it is also desired that the material has a high tensionmodulus or a high compression modulus. The tension modulus of any of theintermediate and outer electrically insulating material layers ispreferably 300 kg/mm² or more, more preferably 400 kg/mm² or more. Thecompression modulus of any of the intermediate and outer electricallyinsulating material layers is preferably 50 kg/mm² or more, morepreferably 100 kg/mm² or more. It is preferred that the intermediateelectrically insulating material layer (and also the outer electricallyinsulating material layer) has at least one modulus value selected fromthe group consisting of a tension modulus of 300 kg/mm² or more and acompression modulus of 50 kg/mm² or more, more advantageously both thesetension modulus value and compression modulus value.

Examples of materials used for the intermediate electrically insulatingmaterial layer include a polyimide resin film, an aromatic polyamideresin film, a polyester resin film, a glass fiber-containing nylon,cellophane, a biaxially oriented polyvinyl alcohol film and apolyphenylene sulfide film. In addition, use can also be made of amulti-layer laminate film obtained by adhering the above-mentionedinsulating materials to other types of electrically insulatingmaterials. An example of a polyimide resin film is Kapton (manufacturedand sold by Du Pont-Toray Co., Ltd., Japan), and an example of anaromatic polyamide resin film is Aramica (manufactured and sold by AsahiKasei Kogyo Kabushiki Kaisha, Japan). Preferred is Aramica since it hasa tension modulus of 1,000 kg/mm² or more and a compression modulus of100 kg/mm² or more and hence exhibits an excellent mechanical strength.As a polyester resin film, a polyethylene terephthalate film ispreferred since it has a tension modulus of 400 kg/mm² or more. Morepreferred is a polyphenylene sulfide film having a tension modulus of400 kg/mm².

As mentioned above, it is preferred that the intermediate electricallyinsulating material layer has a melting temperature of 260° C. or more.An intermediate electrically insulating material layer having a meltingtemperature in the above-mentioned preferred range provides advantageswhich are different from those achieved when the outer electricallyinsulating material layer has a melting temperature in theabove-mentioned preferred range. That is, by using an intermediateelectrically insulating material layer having a melting temperature inthe above-mentioned preferred range, the occurrence of ashort-circuiting at a high temperature can be reduced, thereby improvingthe safety of the battery. Specifically, when a great amount of heat isgenerated in the terminals or the electrochemical cell due to theapplication of a great amount of electric current to the terminals, orwhen the battery is caused to have a high temperature due to an externalheating, the intermediate electrically insulating material layer havinga melting temperature of 260° C. or more will exhibit an effect tosuppress the occurrence of a short-circuiting between the terminals.Consequently, there can be prevented the occurrence of a thermalrunaway, i.e., an accident that an uncontrollable temperature elevationof an electrochemical cell results in an explosion and a fire.Therefore, the melting temperature of the intermediate electricallyinsulating material layer is preferably 260° C. or more, more preferably265° C. or more, most preferably 270° C. or more. With respect to theouter electrically insulating material layer, the reason why thepreferred melting temperature thereof is 260° C. or more is because suchan outer electrically insulating material layer having a high meltingtemperature can maintain the structural integrity of the battery evenwhen the battery is externally heated or when heat is accidentallygenerated inside the battery.

Examples of electrically insulating materials having a meltingtemperature of 260° C. or more include plastic materials, such aspolyimide, polyetherimide, aromatic polyamide, polyphenylene sulfide,polyether sulfone, poly-para-xylene, polyetheretherketone, syndiotacticpolystyrene, a liquid crystal polymer, polyimide, a fluororesin and aphenolic resin; ceramic materials, such as silica, Si₃N₄, magnesia,alumina and mullite; and composite materials comprising ceramicmaterials and plastic materials.

In the present invention, the melting temperature of an electricallyinsulating material is measured by differential scanning calorimetry(DSC) method. Specifically, the melting temperature of an electricallyinsulating material is determined from the endothermic peak value of aDSC curve obtained by means of a differential scanning calorimeter“DSC7” (manufactured and sold by Perkin Elmer cetus Co., Ltd., U.S.A.)by a method in which the temperature of the material is elevated at atemperature elevation rate of 5° C./min.

It is preferred that the thickness of the optional intermediateelectrically insulating material layer disposed between the innerthermoplastic resin layer and the middle metal foil layer is selected inaccordance with the desired strength of the casing and the desiredweight reduction of the casing. Specifically, the thickness of theintermediate electrically insulating material layer is preferably in therange of from 1 to 100 μm, more preferably from 2 to 80 μm, mostpreferably from 4 to 50 μm.

In view of the high moisture resistance and high flame retardancy, apolyvinylidene chloride resin is preferred for an electricallyinsulating material layer and the inner thermoplastic resin layer.Further, by using a polyvinylidene chloride resin for an electricallyinsulating material layer and the inner thermoplastic resin layer, therecan be prevented a lowering of the moisture resistance even when apinhole is present in the middle metal foil layer. Therefore, the use ofa polyvinylidene chloride resin is commercially advantageous in that notonly the reliability of the battery but also the productivity of theproduction process for the battery can be increased.

As a polyvinylidene chloride resin, there can be mentioned a copolymercomprised of 70 to 98% by weight of vinylidene chloride units and 30 to2% by weight of units of at least one comonomer copolymerizable withvinylidene chloride. The comonomer is selected from the group consistingof unsaturated monomers, such as vinyl chloride, acrylonitrile, acrylicacid, methacrylic acid, an alkyl acrylate in which the alkyl group has 1to 18 carbon atoms, maleic anhydride, an alkyl maleate, itaconic acid,an alkyl itaconate and vinyl acetate. The weight average molecularweight of the vinylidene chloride copolymer is preferably in the rangeof from 70,000 to 150,000. From the viewpoint of achieving an excellentextrusion processability during an extrusion-molding for preparing asheet of such a copolymer, it is preferred that the copolymer comprises30 to 2% by weight of a comonomer selected from the group consisting ofvinyl chloride, methyl acrylate, butyl acrylate and 2-ethylhexylacrylate and 70 to 98% by weight of vinylidene chloride. From theviewpoint of achieving excellent moisture barrier properties andexcellent gas barrier properties, it is more preferred that thecopolymer comprises 8 to 2% by weight of methyl acrylate and 92 to 98%by weight of vinylidene chloride.

As a polyvinylidene chloride resin in the form of a sheet, use may bemade of a sheet generally known as a “K-coat film”, which is obtained bycoating an emulsion of the above-mentioned polyvinylidene chloride resinonto a sheet of polyethylene terephthalate, nylon or polypropylene.

In the present invention, the term “terminal” means a body of anelectroconductive material, which electrically connects theelectrochemical cell to an electrical equipment present outside of thecasing. In the battery of the present invention, terminals extendthrough and protrude from the terminal-withdrawal sites in theelongated, hermetic adhesion area (in which the opposite innerthermoplastic resin layers are melt-adhered to each other) toward theoutside of the pouchy casing. Examples of materials used for theterminals include metals, such as a SUS, nickel, aluminum, copper, anickel-plated SUS, iron and a copper/SUS clad; and electroconductivefilms. From the viewpoint of obtaining a low electrical resistance and ahigh mechanical strength, metals are preferred as materials for theterminals. Among the above-mentioned metals, from the viewpoint of easein connecting the terminals to an outside equipment or an outsidecircuit, preferred are nickel, aluminum and copper, and especiallypreferred are aluminum and copper. When the battery of the presentinvention is a lithium ion battery, it is especially preferred that analuminum terminal is used for the cathode (since an aluminum terminal isadvantageous for an oxidation at the cathode) and that a copper terminalis used for the anode (since a copper terminal is advantageous for areduction at the anode). Terminals made of aluminum or copper are likelyto be bent during the handling and use of a battery having suchterminals, as compared to terminals made of a hard metal, such as a SUS.Therefore, when a conventional battery having a laminate-type casing hasterminals made of aluminum or copper, a short-circuiting between theterminals and the metal foil layer of the casing is likely to occur atthe terminal-withdrawal sites. By contrast, even when the battery of thepresent invention has terminals made of aluminum or copper, ashort-circuiting between the terminals and the metal foil layer of thecasing can be surely prevented. Further, with respect to the battery ofthe present invention, the terminals can be intentionally bent at theterminal-withdrawal sites without the occurrence of a short-circuitingbetween the terminals and the metal foil layer of the casing. Therefore,if desired, the projection area of the battery can be reduced by foldingthe terminals at the terminal-withdrawal sites toward the middle portionof the battery, thereby improving the volume energy density of thebattery.

It is preferred that at least a part of the surface of a terminal madeof a metal is roughened. When the terminals have a roughened surface,the strength of the hermetic seal of the casing at theterminal-withdrawal sites can be increased, thereby greatly improvingnot only the air tightness of the battery but also the prevention of aleaking-out of the electrolytic liquid. This point is explained below.The hermetic seal of the casing tends to be damaged especially when apart of the electrolytic liquid leaks from the electrochemical cellenveloped by the pouchy casing. That is, the electrolytic liquid whichhas leaked from the electrochemical cell is likely to enter theinterface between the terminals and the thermoplastic resin layer at theterminal-withdrawal sites in the elongated, hermetic adhesion area,thereby lowering the adhesion between the terminals and thethermoplastic resin layer, so that a problem arises that not only alowering of the air tightness of the battery but also a leaking-out ofthe electrolytic liquid occurs. The use of metal terminals having aroughened surface can prevent the occurrence of the above-mentionedproblem. It is desired that the roughened part of the surface of theterminal covers at least a part of, more advantageously all of theinterface between the terminal and the inner thermoplastic resin layerat the terminal-withdrawal sites in the elongated, hermetic adhesionarea. From the viewpoint of the productivity of the production processfor the battery, it is more preferred that the entire surface of theterminal is roughened.

With respect to the shape of the terminals, for example, the terminalsmay be in the form of a rod, a strip, a band, a sheet, a coil, a mesh orthe like. The shape of the terminals is not limited to theabove-mentioned examples, and the shape of the terminals can beappropriately selected, taking into consideration the shape of thebattery and the materials used for producing the battery. It ispreferred that the size of the terminals is selected, taking intoconsideration the desired upper limit of the electrical resistance ofthe terminals and the desired strength of the terminals. For example,when the terminal is in the form of a sheet, the thickness of theterminal is preferably in the range of from 5 to 100 μm, more preferablyfrom 6 to 80 μm, most preferably from 7 to 60 μm, and the width of theterminal is preferably in the range of from 2 to 30 mm, more preferablyfrom 3 to 25 mm, most preferably from 4 to 20 mm. However, the size ofthe terminal is not limited to the size as described above, and may beappropriately selected, considering the size of the battery, thematerials used for the casing, the desired upper limit of the electricalresistance of the terminals, and the like.

With respect to the method for roughening the surface of the terminal,for example, the roughening can be conducted by a chemical treatment, amechanical treatment or the like.

Examples of chemical treatments used for roughening the surface of theterminal include an etching treatment using a solution obtained bydissolving an acid, an alkali or the like in an appropriate solvent. Forexample, when the terminal is made of copper, the etching treatment canbe performed using nitric acid, a solution of ferric chloride, or thelike; when the terminal is made of aluminum, the etching treatment canbe performed using a sodium hydroxide solution, a phosphoric acidsolution or the like; and when the terminal is made of a SUS, theetching treatment can be performed using sulfuric acid or the like.Further, depending on the oxidation potential of the metal terminal, itis possible to roughen the surface of the metal terminal by subjectingit to cathode oxidation in an electrolytic liquid. The roughening methodutilizing cathode oxidation is preferred for roughening a terminal madeof copper or aluminum since copper and aluminum are susceptible tocathode oxidation.

Examples of mechanical treatments used for roughening the surface of theterminal include a method in which the surface of the terminal issubjected to scraping by means of, for example, a rasp, a whetstonecontaining a vinyl polymer as a binder, a belt sander or a scratchwheel.

As a further example of methods for roughening the surface of aterminal, there can be mentioned a plasma etching. The method forroughening the surface of the metal terminal is not limited to theabove-mentioned examples, and can be appropriately selected consideringthe material used for the terminal.

With respect to the measurement of the surface roughness of a metalterminal, the measurement can be conducted using an instrument having astylus, an instrument utilizing the light wave interference, and thelike. In the present invention, when the terminal is in the form of asheet, the surface roughness thereof can be determined by a method inwhich a sample having a size of 1.5 cm×4.5 cm is prepared, and thesurface roughness of the sample is measured using a stylus type surfaceroughness measuring instrument (“alpha-step 200”, manufactured and soldby TENCOR INSTRUMENTS, U.S.A.) under conditions wherein the scanningwidth is 0.4 mm and the scanning rate is 1 sec/μm. When the terminal isin a form other than a sheet, the surface roughness thereof can bemeasured in accordance with JIS B0652-1973 by a surface roughnessmeasuring instrument utilizing the light wave interference.

In the present invention, with respect to a terminal which is in theform of a sheet, when the surface of the terminal is referred to asbeing “roughened”, it means that the surface of the terminal has aroughness (Ra) of 0.3 μm or more or a total indicator runout (TIR) valueof 2 μm or more, each as measured using the above-mentioned stylus typesurface roughness measuring instrument. The Ra value of the sheet formterminal is preferably in the range of from 0.34 to 30 μm, and the TIRvalue of the sheet form terminal is preferably in the range of from 2.5to 30 μm.

In the present invention, with respect to a terminal which is in a formother than a sheet, when the surface of the terminal is referred to asbeing “roughened”, it means that the surface of the terminal has amaximum roughness (Rmax) of 2 μm or more, preferably 2.5 μm or more, asmeasured in accordance with JIS B0652-1973 by a surface roughnessmeasuring instrument utilizing the light wave interference.

In general, it is preferred that the water permeability of a casing fora non-aqueous battery of a thin configuration is as low as possible.With respect to the casing used in the battery of the present invention,the water permeability of the casing is preferably 1 g/m² 24 hours orless, more preferably 0.2 g/m² 24 hours or less, most preferably 0.1g/m² 24 hours or less. When a casing having a water permeability of morethan 1 g/m² 24 hours is used, the electrochemical cell enveloped by thecasing absorbs water which enters the inside of the casing, and theabsorbed water causes a deterioration of the electrochemical cell and alowering of the battery capacity. Further, it is possible that the waterabsorbed by the electrochemical cell causes a decomposition of theelectrolyte in the cell and a gas is generated by the decomposition ofthe electrolyte. The water permeability of the casing can be determinedby a method comprising filling the inside of the casing with apredetermined weight of a water-absorptive material, such as calciumchloride anhydride, followed by a hermetic sealing of the casing;maintaining the resultant sealed casing containing a water-absorptivematerial in a moisture-containing atmosphere for a predetermined time;and measuring the difference in the weight of the sealed casing(containing the water-absorptive material) before and after themaintenance thereof in the above-mentioned atmosphere.

In the process for producing the battery of the present invention, themelt-adhesion for hermetically sealing the casing may be performed whilemaintaining the inside of the casing under vacuum. By maintaining theinside of the casing under vacuum during the melt-adhesion for sealingthe casing, the electrochemical cell can be tightly enveloped by thecasing, so that not only can the electrochemical cell be securely heldat a certain position in the casing but also the heat dissipation fromthe electrochemical cell can be improved. With respect to the method forsealing the casing while maintaining the inside of the casing undervacuum, there can be mentioned a method in which the inside of anon-sealed casing containing an electrochemical cell is deaeratedthrough a nozzle and, immediately thereafter, the casing is sealed bymelt-adhesion, and a method in which a non-sealed casing containing anelectrochemical cell is placed in an airtight chamber, and theatmosphere of the airtight chamber is evacuated, followed by a sealingof the casing by melt-adhesion.

The non-aqueous battery of a thin configuration of the present inventionis advantageous when the electrochemical cell enveloped by the casing isof a lithium type or a lithium ion type, and especially advantageouswhen the electrochemical cell is of a lithium ion type. A lithium ionbattery is comprised of a cathode, an anode, a separator disposedbetween and connected to the cathode and the anode wherein the separatoris capable of passing lithium ions therethrough, an electrolyte,terminals and a casing. In such a battery, each electrode has astructure in which a current collector has thereon an electrode activematerial, and the current collector is connected to a terminal (see, forexample, U.S. Pat. No. 4,997,732).

Examples of methods for connecting a terminal to a current collectorinclude ultrasonic welding, resistance welding, and laser welding. Theconnection between a terminal and a current collector can be made eitherbefore or after the assembly of the electrochemical cell. The battery ofthe present invention encompasses a battery having a structure whereineach of the cathode current collector and the anode current collector isconnected to at least one corresponding terminal or a plurality ofcorresponding terminals; and a battery having a structure wherein aplurality of unit cells each comprising a laminate of a“cathode/separator/anode” structure are connected to each other inparallel or in series and terminals are connected to the currentcollectors.

In the battery of the present invention, an absorbent for carbon dioxidemay be placed inside the casing so as to suppress an increase in theinternal pressure. By suppressing an increase in the internal pressure,the air tightness of the battery can be maintained for a prolongedperiod of time.

Examples of absorbents for carbon dioxide include hydroxides or oxidesof metals belonging to Group I or II of the Periodic Table, such asLiOH, NaOH, KOH, Ca(OH)₂, Ba(OH)₂, Li₂O, CaO and ascarite; and syntheticzeolites which can serve as a molecular sieve, such as the molecularsieves sold by the trade names of Molecular sieve 4A, Zeolam A-4, andMolecurite A-430. These absorbents for carbon dioxide not only have ahigh absorbing ability for carbon dioxide, but are also easy to handlebecause they are solid. The manner of use of the absorbents for carbondioxide is as follows. For example, an absorbent (for carbon dioxide) inthe form of pellets, particles or a powder is wrapped in a resin filmhaving a high gas permeability (such as poly(perfluoroolefin sulfonicacid (trade name: Nafion), cellophane, a polyethylene film, apolypropylene film or a stretched polyethylene film), and the absorbentwrapped in the resin film is put into the pouchy casing together withthe electrochemical cell. Alternatively, an absorbent for carbon dioxidemay be used in the form of a dispersion thereof in an electrolyticliquid, a solid electrolyte or an electrode active material.

When the electrochemical cell inside the casing undergoes an overcharge,a discharge of a large amount of current or an abnormal reaction due toa short-circuiting, the cell frequently generates a gas by a chemicalreaction or by an abnormal rise in the internal temperature. In apreferred embodiment of the present invention, even when such a gasgeneration occurs inside the battery, the battery exhibits advantagesnot only in that an expansion-distortion of the casing can be suppressedto a minimum, thus preventing the equipment containing the battery fromsuffering a damage, but also in that, by promoting the heat conductionfrom the electrochemical cell to the casing, the battery can beprevented from undergoing a thermal runaway and hence maintained in asafe condition. In the battery of the present invention, for suppressingan increase in the internal pressure due to a gas generation (fromabnormal reactions or the like) inside the battery, the battery may havegas-release means adapted to be actuated to release at least a part ofthe generated gas when the internal pressure exceeds the externalpressure. As such gas-release means, for example, a safety valveprovided in the wall of the casing can be effectively employed. As asafety valve, there can be mentioned a valve which can be opened tocommunicate the inside and the outside of the casing to each other andwhich has a structure wherein a holder portion of the valve is securedto the casing and the opening means thereof is actuated by a spring or amagnetic coupling. When the internal pressure of the battery hasincreased to a predetermined high level, the valve is automaticallyopened to thereby release the gas inside the casing to the outside ofthe casing. Further, depending on the type of the opening means of thesafety valve, the internal pressure required for actuating the openingmeans can be lowered when the internal temperature of the battery is ata temperature which is the same as or higher than the predetermined hightemperature. Examples of means for actuating the opening means of thevalve include a spring, a push plate, and a magnetic coupling. Thepressure required for opening the valve can be appropriately set byselecting the area of the opening and the stress required for openingthe valve. Alternatively, the gas-release when the internal pressure hasreached a predetermined high level can also be achieved by a method inwhich, before the melt-adhesion for sealing the casing, a thin filmexhibiting a relatively low adhesion to the inner thermoplastic resinlayer of the laminate is interposed between the opposite sheets of thelaminates (each having the thermoplastic resin layer as the innermostlayer) at a position corresponding to a portion of the elongated,hermetic adhesion area to be formed.

Further, the battery of the present invention may contain means to breakthe electrical connection between the terminals and the electrochemicalcell in response to a change caused by an increase in the internalpressure and/or internal temperature of the battery. Specifically, thebattery of the present invention may contain means adapted to beactuated to cut at least a part of the terminal when the pouchy casingsuffers expansion and distortion. Such means will prevent a fire, anexplosion, a thermal runaway and the like even when an accident occursin the battery, thereby improving the safety of the battery.

With respect to the means adapted to be actuated to cut at least a partof the terminal in response to the occurrence of expansion anddistortion of the casing, such means can be realized by, for example,any of the following structures (1) to (3):

(1) a structure wherein the terminal is made of a laminate comprised oftwo or more layers of flat metal sheets which can be peeled off fromeach other, and one of the outermost layers of the terminal has theinner end thereof connected to the electrochemical cell and has theouter end thereof terminating inside the casing, and the other outermostlayer of the terminal has the outer end thereof leading to the outsideof the casing and has the inner end thereof not connected to theelectrochemical cell, and wherein both outermost layers of the terminalare, respectively, fixedly adhered to the opposite inner thermoplasticresin layers of the casing;

(2) a structure wherein a middle portion of the terminal, which ispositioned in the casing, has a low breaking strength, and portions ofthe terminal which are, respectively, positioned on the inner and outersides of, and in adjacent to, the middle portion (having a low breakingstrength) are, respectively, fixedly adhered to the opposite innerthermoplastic resin layers of the casing; and

(3) a structure wherein both terminals connected to the cathode and theanode of the electrochemical cell are, respectively, fixedly adhered tothe opposite inner thermoplastic resin layers of the casing.

With respect to the above-mentioned structure (1), the lamination of theflat metal sheets for producing the laminate type terminal can beperformed by welding, such ultrasonic welding, laser welding and spotwelding, or by using, as an adhesive, an electrically conductive coatingmaterial. The adhesion strength between the layers of flat metal sheetscan be adjusted by selecting the lamination method, connecting materialsused for the lamination and the area of a connected portion betweenadjacent layers of the laminate.

With respect to the above-mentioned structure (2), the. middle portionof the terminal which portion has a low breaking strength can beprovided, for example, by a method in which a middle portion of theterminal is partly cut (nicked) so as to cause the terminal to have areduced cross-sectional area at the middle portion, and a method inwhich the terminal is produced using two types of metals havingdifferent breaking strengths, wherein a middle portion of the terminalis formed using the metal having a lower breaking strength, and theinner and outer sides of the middle portion are formed using the othermetal having a higher breaking strength.

With respect to the above-mentioned structure (3), the stress requiredfor breaking at least a part of the terminal can be adjusted byadjusting the adhesion strength between the terminal and the currentcollector of or the electrode active material of the electrode laminatein the electrochemical cell.

For providing any of the above-mentioned structures (1) to (3), it isnecessary that one surface of a portion of the terminal be fixedlyadhered to one of the opposite inner thermoplastic resin layers of thecasing. while preventing the other surface of the same portion of theterminal from being fixedly adhered to the other of the opposite innerthermoplastic resin layers of the casing. A fixed adhesion between aninner thermoplastic resin layer of the casing and a surface of theterminal can be achieved by a method in which an inner thermoplasticresin layer of the casing is directly melt-adhered to a surface of theterminal. On the other hand, a non-fixed separable adhesion between aninner thermoplastic resin layer of the casing and a surface of theterminal can be achieved by a method in which, before melt-adhering theinner thermoplastic resin layer to the terminal, a portion of theterminal which portion should be prevented from being fixedly adhered tothe inner thermoplastic resin layer is covered with a powder or a sheetof a material exhibiting a poor adhesion to the inner thermoplasticresin layer. Examples of materials exhibiting a poor adhesion to theinner thermoplastic resin layer include fluororesins, such aspolytetrafluoroethylene (trade name: Teflon). There is no particularlimitation with respect to the breaking strength of the part of theterminal to be cut when the casing suffers expansion and distortion, andthe appropriate breaking strength varies depending on the capacity andstructure of the battery. However, the appropriate breaking strength ispreferably in the range of from 10 g to 50 kg.

Further, an element capable of breaking the electrical connectionbetween the terminal and the electrochemical cell in response to anincrease in the internal temperature (i.e.; PTC element) can beconnected to the terminal. The PTC element contains a compositioncomprising an electrically conductive filler and an electricallyinsulating resin. The PTC element functions by utilizing a difference inthermal expansion coefficient between the electrically conductive fillerand the electrically insulating resin. When the PTC element is exposedto a high temperature, the PTC element exhibits an increased electricalresistance and thus breaks the electrical connection between theterminal and the electrochemical cell. In general, the PTC element iscomprised of a three-layer laminate of a flat metal sheet, a layer of acomposition comprising an electrically conductive filler and anelectrically insulating resin and a flat metal sheet, and it can beconnected to the terminal as a part thereof either inside or outside thebattery casing.

Alternatively, the function of the PTC element can also be achieved byusing a terminal having a laminate structure wherein at least twoelongated flat metal sheets are laminated through a composite materiallayer comprising an electrically conductive adhesive or an electricallyconductive adhesive tape, an electrically conductive filler and anelectrically insulating resin, wherein one of the outermost elongatedmetal sheets has the inner end thereof connected to the electrochemicalcell and has the outer end thereof terminating inside the casing, andthe other outermost elongated metal sheet has the outer end thereofleading to the outside of the casing and has the inner end thereof notconnected to the electrochemical cell. The value of electric resistancewhich is exhibited when this terminal is exposed to a high temperature,and the temperature at which this terminal exhibits an sharp increase inthe electric resistance thereof can be adjusted by changing theformulation of the composite material layer, i.e., the type and amountof the electrically conductive filler (e.g., a powder of a metal, suchas silver or copper), the type and amount of the electrically insulatingresin (such as phenol resin or an epoxy resin), the type and amount ofthe electrically conductive adhesive, the type and amount of theelectrically conductive adhesive tape, and the area covered by theadhesive or the tape. Thus, the internal resistance of the battery andthe operation temperature thereof can be controlled by using the aboveterminal. Different types of metals can be easily connected to eachother by conventional methods. For example, when a nickel foil isadhered to one end portion of an aluminum terminal by using anelectrically conductive tape, it becomes easy to perform a soldering onthis end portion of the terminal, so that it becomes easy to connect theend portion of the terminal to an outside equipment by soldering. Thissoldering method can also be used for the lamination of the flat metalsheets mentioned in connection with the above-mentioned structure (1)for realizing the means adapted to be actuated to cut at least a part ofthe terminal in response to the occurrence of expansion and distortionof the casing.

When the battery of the present invention is a lithium battery or alithium ion battery, nickel or aluminum is used as a cathode currentcollector, and copper is used as an anode current collector. Examples ofcathode active materials include compound oxides of alkali metals, suchas LiCoO₂; compound oxides of alkali metals with non-alkali metal oxides(such as MnO₂) or non-alkali metal hydroxides; oxides of vanadium, suchas V₂O₅; oxides of chromium, such as Cr₂O₅; dichalcogenides oftransition metals, such as TiS₂, MoS₂ and FeS₂; trichalcogenides oftransition metals, such as NbSe₃; Chevrel compounds (A_(x)Mo₆Y₈, whereinA=Li or Cu, and Y=S or Se); organic compounds, such as polypyrrole, anddisulfide derivatives; and mixtures thereof.

Examples of anode active materials include metal lithium; lithiumalloys; carbonaceous materials which are capable of occluding lithium,such as a needle coke and a graphite; lithium solid solutions of metaloxides, such as tin compound oxides; electrically conductive polymerscapable of doping and dedoping lithium. In the electrochemical cell ofthe battery of the present invention, the cathode and the anode areconnected to each other through a separator, and the separator is madeof a material capable of passing ions therethrough.

As examples of the ion transfer medium employed in the separatordisposed between the cathode and the anode, there can be mentioned aliquid electrolyte, a gel type electrolyte and a solid electrolyte. Agel type electrolyte is comprised of a matrix polymer material, anorganic solvent and a solute. Examples of matrix polymer materialsinclude a polyvinylidene fluoride polymer and a polyacrylonitrilepolymer; examples of organic solvents include ethylene carbonate,propylene carbonate, γ-butyrolactone, 1,2-dimethoxyethane,tetrahydrofuran; and examples of solutes include LiClO₄, LiPF₆ andLiBP₄.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described in more detail with reference toExamples and Comparative Examples, which should not be construed aslimiting the scope of the present invention.

In the following Examples and Comparative Examples, the terms “positiveelectrode” and “negative electrode” are used instead of the terms“cathode” and “anode”, respectively.

EXAMPLE 1

A powder of lithium cobalt oxide (LiCoO₂; average particle diameter: 10μm) and carbon black were added to and dispersed in a 5% by weightsolution of polyvinylidene fluoride (as a binder) in N-methylpyrrolidone(NMP), so that a mixture containing solid components in the followingdry weight ratio was obtained: LiCoO₂ (85%), carbon black (8%) andpolyvinylidene fluoride (7%). The obtained mixture was applied onto analuminum sheet (thickness: 15 μm) (as a current collector) and dried,followed by heat-pressing, to thereby prepare a positive electrode layerhaving a thickness of 115 μm and a density of 2.8 g/cm³. The aluminumsheet having the prepared positive electrode layer thereon was used as apositive electrode sheet. A powder of needle coke (NC) having an averageparticle diameter of 12 μm was homogeneously mixed with a 5% by weightsolution of polyvinylidene fluoride in NMP, thereby obtaining a slurry(NC/polymer dry weight ratio=92:8). The obtained slurry was applied ontoa copper sheet (as a current collector) by doctor blade method anddried, followed by heat-pressing, to thereby prepare a negativeelectrode layer having a thickness of 125 μm and a density of 1.2 g/cm³.The copper sheet having the prepared negative electrode layer thereonwas used as a negative electrode sheet.

A hexafluoropropylene/vinylidene fluoride copolymer resin(hexafluoropropylene content: 5% by weight) was subjected to extrusionmolding by means of an extruder (manufactured and sold by ToshibaMachine Co., Ltd., Japan) at an extrusion die temperature of 230° C.,thereby preparing a sheet having a thickness of 150 μm. The preparedsheet was irradiated with electron beams (irradiation dose: 10 Mrads) tothereby obtain a crosslinked sheet, and then, the crosslinked sheet wasvacuum dried at 60° C. to remove by-produced hydrogen fluoride (HF) gas.The crosslinked sheet was further irradiated with electron beams(irradiation dose: 15 Mrads), and subsequently, the irradiatedcrosslinked sheet was immersed in a mixture of flon HFC134a and water(flon/water weight ratio=99:1), using a tightly sealed container, at 70°C. under a pressure of 20 kg/cm² for 24 hours, thereby obtaining animpregnated sheet (liquid content: 6.5% by weight). The impregnatedsheet was taken out from the container and, immediately thereupon,placed in an oven maintained at 210° C. to thereby heat the impregnatedsheet to 180° C. over 10 sec. As a result, a white porous sheet having athickness of 270 μm (expansion ratio: 8 times) was obtained. The ratioof closed cells in the porous sheet was 87% by volume as measured bymeans of 930 type air-comparison gravimeter (manufactured and sold byToshiba Beckman Co., Ltd., Japan). The obtained porous sheet wasimmersed in a non-aqueous electrolytic solution obtained by dissolvinglithium tetrafluoroborate (LiBF₄) in a mixed solution of ethylenecarbonate (EC), propylene carbonate (PC) and γ-butyrolactone (γ-BL)(EC/PC/γ-BL weight ratio=1:1:2, and LiBF₄ concentration: 1 mol/liter) at100° C. for 2 hours to thereby impregnate and swell the porous sheetwith the electrolytic solution. The thickness of the impregnated poroussheet was 350 μm, and this sheet was used as a hybrid solid electrolytesheet.

The following operations were conducted in an atmosphere having a dewpoint of −50° C. or less.

Each of the positive electrode sheet (having the positive electrodelayer on one side thereof) and the negative electrode sheet (having thenegative electrode layer on one side thereof) was fabricated so as tohave a size of 6 cm×50 cm. The hybrid solid electrolyte sheet wasfabricated so as to have a size of 6.5 cm×52 cm. Then, the thus obtainedpositive electrode sheet, hybrid solid electrolyte sheet and negativeelectrode sheet were laminated so that the hybrid solid electrolytesheet was interposed between the positive and negative electrode sheets,and the positive electrode layer of the positive electrode sheet and thenegative electrode layer of the negative electrode sheet were oppositeto each other through the hybrid solid electrolyte sheet, therebyobtaining a positive electrode/electrolyte/negative electrode laminate.A rigid aluminum foil having a width of 1 cm, a length of 10 cm and athickness of 50 μm (Ra=0.16 μm and TIR=0.73 μm) as a positive terminal,and a rigid milled copper foil having a width of 1 cm, a length of 10 cmand a thickness of 50 μm (Ra=0.07 μm and TIR=0.91 μm) as a negativeterminal were respectively connected to the current collectors of thepositive and negative electrode sheets which are both outermost layersof the positive electrode/electrolyte/negative electrode laminate bymeans of an ultrasonic metal welder (USW-200Z38S, manufactured and soldby Ultrasonic Engineering Co., Ltd., Japan). The terminals were,respectively, connected to the current collectors so that the center ofthe longitudinal axis of the terminal is positioned in a 6 cm-side ofthe current collector at a distance of 2 cm from one end of the width(namely, at a distance of 4 cm from the other end of the width) of theelectrode sheet. Next, the positive electrode/electrolyte/negativeelectrode laminate with the terminals (namely, electrode assembly havinga length of 50 cm) were accordion folded at intervals of 10 cm so as tohave five folds, thereby obtaining an electrochemical cell.

A laminate shown in FIGS. 1(a) and 1(b) for producing a pouchy casing ofa battery was prepared in the following manner. Three different sheetsrespectively of a stretched nylon film (trade name: Unilon, manufacturedand sold by Idemitsu Petrochemical Co., Ltd., Japan) having a length of18 cm, a width of 14 cm and a thickness of 15 μm; an aluminum foilhaving a length of 18 cm, a width of 14 cm and a thickness of 7 μm; andan L-LDPE film (trade name: LS-700C, manufactured and sold by IdemitsuPetrochemical Co., Ltd., Japan) having a length of 18 cm, a width of 14cm and a thickness of 50 μm, were put one upon another in this order, inwhich the sheets were adhered using a two-pack urethane adhesive toobtain a laminate. Prior to the lamination, portions of the 18 cm-sideof the aluminum foil in the laminate were partly cut-out with respect tothe peripheral edge thereof to form cut-out portions each having a width(in a direction parallel to the peripheral edge) of 11 mm and a depth(in a direction perpendicular to the peripheral edge) of 0.5 mm, whereinthe cut-out portions correspond to the terminal withdrawal sites. Thelaminate was folded in two about a folding line ]1 as shown in FIG.1(a), thereby obtaining a folded laminate having a size of 0.9 cm×14 cm.With respect to each of three pairs of opposite sides (i.e., a pair ofopposite 9 cm-sides free of cut-out portions and two pairs of opposite14 cm-sides) of the folded laminate, the opposite sides weremelt-adhered to each other over a width of 10 mm from the peripheraledge thereof by heating at 140° C. for 6 seconds to thereby form ahermetic seal, thus providing a pouchy casing having an opening in theremaining pair of opposite 9 cm-sides and having terminal-withdrawalsites at the opening thereof. The electrochemical cell prepared abovewas placed into the obtained pouchy casing and the terminals were takenout from the opening of the pouchy casing through theterminal-withdrawal sites. The opening of the pouchy casing washermetically sealed by heating at 120° C. under a pressure of 1 kg/cm²for 6 seconds, thereby obtaining a battery shown in FIG. 1(c). At theterminal-withdrawal sites of the pouchy casing, the width of theelongated, hermetic adhesion area was 10 mm from the peripheral edge ofthe pouchy casing. As mentioned above, each of the cut-out portions ofthe aluminum foil layer had a width of 11 mm and a depth of 0.5 mm asmeasured from the peripheral edge of the pouchy casing. The depth of thecut-out portion was confirmed under an optical microscope (System MetalMicroscope BHT, manufactured and sold by Olympus Optical Co., Ltd.,Japan) using an objective micrometer graduated in 0.01 millimeters(manufactured and sold by Olympus Optical Co., Ltd., Japan).

Five batteries having a construction as shown in FIG. 1(c) were preparedas described above. The prepared batteries were subjected tocharge/discharge cycle testing using a charge/discharge testing device(Model HJ-101SM6, manufactured and sold by Hokuto Denko Corporation,Japan). All of the five batteries were capable of standardcharge/discharge operation and their average discharge capacity was 900mAh. None of the batteries charged at a constant voltage of 4.2 Vsuffered voltage-lowering or heat-generation caused by short-circuitingeven when the terminals were folded. Further, no leakage of liquid wasobserved.

In addition, a pouchy casing was prepared in substantially the samemanner as mentioned above, and 20 g of calcium chloride anhydride wassealed up inside the pouchy casing, instead of the electrochemical cell.The sealed pouchy casing containing calcium chloride was placed at atemperature of 60° C. and a relative humidity (RH) of 90% for 3 months,but the increase in the weight of the pouchy casing was less than 1 mg.

EXAMPLE 2

A laminate shown in FIGS. 2(a) and 2(b) for producing a pouchy casingfor a battery was prepared in the following manner. Three differentsheets respectively of a polyethylene terephthalate film (trade name:Melinex S, manufactured and sold by ICI Japan Ltd., Japan) having alength of 18 cm, a width of 14 cm and a thickness of 12 μm; an aluminumfoil having a length of 18 cm, a width of 13 cm and a thickness of 9 μm;and an L-LDPE film (trade name: LS-700C, manufactured and sold byIdemitsu Petrochemical Co., Ltd., Japan) having a length of 18 cm, awidth of 14 cm and a thickness of 50 μm, were put one upon another inthis order, wherein the sheets were trued up on their respective one 18cm-sides. The sheets were adhered using a two-pack urethane adhesive toobtain a laminate. The aluminum foil in the laminate was cut-out alongthe entire length of one 18 cm-side of the foil by a depth (in adirection perpendicular to the peripheral edge of the foil) of 10 mm asmeasured from the peripheral edge of the laminate. The thermoplasticresin layer and the electrically insulating material layer (polyethyleneterephthalate film layer and L-LDPE film layer) of the laminate werecut-away using a knife along the entire length of the 18 cm-side (whichis on the same side as the 10 mm cut-away side of the aluminum foil) bya depth of 0.98 cm, to thereby obtain a laminate in which the aluminumfoil is cut-out along the entire length of the above-mentioned 18cm-side of the aluminum foil layer by a depth of 0.2 mm from theperipheral edge of the laminate. {Therefore, as shown in FIG. 2(a), thesize of the laminate became 18 cm×13.02 cm.} The laminate was folded intwo about a folding line ]2 as shown in FIG. 2(a), thereby obtaining afolded laminate having a size of 9 cm×13.02 cm. With respect to each ofthree pairs of opposite sides (i.e., a pair of opposite 9 cm-sides freeof a cut-out portion and two pairs of opposite 13.02 cm-sides) of thefolded laminate, the opposite sides were melt-adhered to each other overa width of 10 mm from the peripheral edge thereof by heating at 140° C.for 6 seconds to thereby form a hermetic seal, thus providing a pouchycasing having an opening in the remaining pair of opposite 9 cm-sidesand having terminal-withdrawal sites at the opening thereof.

An electrochemical cell prepared in substantially the same manner as inExample 1 was placed into the prepared pouchy casing and terminals weretaken out of the opening of the pouchy casing through theterminal-withdrawal sites. The opening of the pouchy casing washermetically sealed by heating at 120° C. under a pressure of 1 kg/cm²for 6 seconds, thereby obtaining a battery shown in FIG. 2(c). At theterminal-withdrawal sites of the pouchy casing, the width of theelongated, hermetic adhesion area was 3 mm from the peripheral edge ofthe pouchy casing. As mentioned above, the aluminum foil layer wascut-out along the entire length of the 18 cm-side of the foil by a depthof 0.2 mm as measured from the peripheral edge of the pouchy casing. Thedepth of the cut-out portion was confirmed under an optical microscope(System Metal Microscope BHT, manufactured and sold by Olympus OpticalCo., Ltd., Japan) using an objective micrometer graduated in 0.01millimeters (manufactured and sold by Olympus Optical Co., Ltd., Japan).

Five batteries having a construction as shown in FIG. 2(c) were preparedas described above. The prepared batteries were subjected tocharge/discharge cycle testing using a charge/discharge testing device(Model HJ-101SM6, manufactured and sold by Hokuto Denko Corporation,Japan). All of the five batteries were capable of standardcharge/discharge operation and their average discharge capacity was 900mAh. None of the batteries charged at a constant voltage of 4.2 Vsuffered voltage-lowering or heat-generation caused by short-circuitingeven when the terminals were folded. Further, no leakage of liquid wasobserved.

In addition, a pouchy casing was prepared in substantially the samemanner as mentioned above, and 20 g of calcium chloride anhydride wassealed up inside the pouchy casing, instead of the electrochemical cell.The opening of the pouchy casing was hermetically sealed in a width of10 mm from the peripheral edge thereof by heating at 140° C. for 6seconds. The sealed pouchy casing containing calcium chloride was placedat a temperature of 60° C. and a relative humidity (RH) of 90% for 3months, but the increase in the weight of the pouchy casing was lessthan 1 mg.

EXAMPLE 3

A laminate shown in FIGS. 3(a) and 3(b) for producing a pouchy casingfor a battery was prepared in the following manner. Three differentsheets respectively of a polyethylene terephthalate film (trade name:Melinex S, manufactured and sold by ICI Japan Ltd., Japan) having alength of 18.9 cm, a width of 14 cm and a thickness of 12 μm; analuminum foil having a length of 17.9 cm, a width of 13 cm and athickness of 20 μm; and a polyethylene-vinyl alcohol copolymer film(trade name: EF-HS, manufactured and sold by Kuraray Co., Ltd., Japan)having a length of 18.9 cm, a width of 14 cm and a thickness of 30 μm,were put one upon another in this order, wherein the respective centersof the three sheets were in register with one another in which thesheets were adhered using a two-pack urethane adhesive to obtain alaminate. The thermoplastic resin layer and the electrically insulatingmaterial layer (polyethylene terephthalate film layer andpolyethylene-vinyl alcohol copolymer film layer) of the laminate werecut-away along the entire length of all four sides of the laminate sothat the aluminum foil layer in the laminate was cut-out by a depth of0.5 mm as measured from the peripheral edge of the laminate. {Thereforeas shown in FIG. 3(a), the size of the laminate became 18 cm×13.1 cm.}The laminate was folded in two about a folding line ]3 as shown in FIG.3(a), thereby obtaining a folded laminate having a size of 9 cm×13.1 cm.With respect to each of three pairs of opposite sides (i.e., a pair ofopposite 9 cm-sides and two pairs of opposite 13.1 cm-sides) of thefolded laminate, the opposite sides were melt-adhered to each other overa width of 10 mm from the peripheral edge thereof by heating at 140° C.for 6 seconds to thereby form a hermetic seal, thus providing a pouchycasing having an opening in the remaining pair of opposite 9 cm-sidesand having terminal-withdrawal sites at the opening thereof.

An electrochemical cell prepared in substantially the same manner as inExample 1 was placed into the prepared pouchy casing and the terminalswere taken out from the opening of the pouchy casing through theterminal-withdrawal sites. The opening of the pouchy casing washermetically sealed by heating at 135° C. under a pressure of 1 kg/cm²for 5 seconds, thereby obtaining a battery shown in FIG. 3(c). At theterminal-withdrawal sites of the pouchy casing, the width of theelongated, hermetic adhesion area was 10 mm from the peripheral edge ofthe pouchy casing. As mentioned above, the aluminum foil layer wascut-out along the entire length of all four sides of the foil in a depthof 0.5 mm as measured from the peripheral edge of the pouchy casing. Thedepth of the removed portion was confirmed under an optical microscope(System Metal Microscope BHT, manufactured and sold by Olympus OpticalCo., Ltd., Japan) using an objective micrometer graduated in 0.01millimeters (manufactured and sold by Olympus Optical Co., Ltd., Japan).

Five batteries having a construction as shown in FIG. 3(c) were preparedas described above. The prepared batteries were subjected tocharge/discharge cycle testing using a charge/discharge testing device(Model HJ-101SM6, manufactured and sold by Hokuto Denko Corporation,Japan). All of the five batteries were capable of standardcharge/discharge operation and their average discharge capacity was 900mAh. None of the batteries charged at a constant voltage of 4.2 Vsuffered voltage-lowering or heat-generation caused by short-circuitingeven when the terminals were folded. Further, no leakage of liquid wasobserved.

In addition, a pouchy casing was prepared in substantially the samemanner as mentioned above, and 20 g of calcium chloride anhydride wassealed up inside the pouchy casing, instead of the electrochemical cell.The opening of the pouchy casing was hermetically sealed in a width of10 mm from the peripheral edge thereof by heating at 140° C. for 6seconds. The sealed pouchy casing containing calcium chloride was placedat a temperature of 60° C. and a relative humidity (RH) of 90% for 3months, but the increase in the weight of the pouchy casing was lessthan 1 mg.

EXAMPLE 4

A laminate was prepared in the following manner. Three different sheetsrespectively of a polyimide film (trade name: Kapton, manufactured andsold by Du Pont-Toray Co., Ltd., Japan) having a length of 18 cm, awidth of 14 cm and a thickness of 12.5 μm; an aluminum foil having alength of 18 cm, a width of 13 cm and a thickness of 20 μm; and a heatadhesive polybutylene terephthalate film (trade name: Estina,manufactured and sold by Sekisui Chemical Co., Ltd., Japan) having alength of 18 cm, a width of 14 cm and a thickness of 30 μm, were put oneupon another in this order, wherein the sheets were trued up on theirrespective one 18 cm-sides. The sheets were adhered using a two-packurethane adhesive to obtain a laminate. With respect to the polyimidefilm used in the laminate, the polyimide film exhibited no meltingtemperature as measured by DSC method. The aluminum foil in the laminatewas cut-out along the entire length of one 18 cm-side of the foil by adepth (in a direction perpendicular to the peripheral edge of the foil)of 10 mm as measured from the peripheral edge of the laminate. Thelaminate was folded in two about a central line perpendicularlytraversing both 18 cm-sides thereof, thereby obtaining a folded laminatehaving a size of 9 cm×14 cm. With respect to each of two pairs ofopposite sides (i.e., a pair of opposite 9 cm-sides free of a cut-outportion and two pairs of opposite 14 cm-sides) of the folded laminate,the opposite sides were melt-adhered to each other over a width of 10 mmfrom the peripheral edge thereof by heating at 180° C. for 8 seconds tothereby form a hermetic seal, thus providing a pouchy casing having anopening in the remaining pair of opposite 9 cm-sides and havingterminal-withdrawal sites at the opening thereof. An electrochemicalcell prepared in substantially the same manner as in Example 1 wasplaced into the prepared pouchy casing and the terminals were taken outof the opening of the pouchy casing through the terminal-withdrawalsites. The opening of the pouchy casing was hermetically sealed byheating at 185° C. for 5 seconds, thereby obtaining a battery. At theterminal-withdrawal sites of the pouchy casing, the width of theelongated, hermetic adhesion area was 20 mm from the peripheral edge ofthe pouchy casing. As mentioned above, the aluminum foil layer wascut-out along the entire length of the 18 cm-side of the foil by a depthof 10 mm as measured from the peripheral edge of the pouchy casing. Thedepth of the cut-out portion was confirmed using a scale graduated in 1millimeters.

Five batteries were prepared as described above. All of the fivebatteries were capable of standard charge/discharge operation and theiraverage discharge capacity was 900 mAh. None of the batteries charged ata constant voltage of 4.2 V suffered voltage-lowering andheat-generation caused by short-circuiting even when the terminals werefolded. Further, no leakage of liquid was observed.

When a battery having a capacity of 905 mAh was charged at a constantvoltage of 4.2 V and was placed in an oven (250° C.), gas effused fromthe adhesion area between the terminals and the laminate of the pouchycasing, but the laminate did not catch fire. In addition, when a batteryhaving a capacity of 850 mAh was subjected to a charging operation at aconstant current of 1.8 A, gas effusion was observed, but the laminatedid not catch fire.

EXAMPLE 5

A laminate was prepared in the following manner. Four different sheetsrespectively of a polyethylene terephthalate film (trade name: MelinexS, manufactured and sold by ICI Japan Ltd., Japan) having a length of 18cm, a width of 14 cm and a thickness of 12 μm; an aluminum foil having alength of 18 cm, a width of 13 cm and a thickness of 9 μm; apolyethylene terephthalate film (trade name: Melinex S, manufactured andsold by ICI Japan Ltd., Japan) having a length of 18 cm, a width of 14cm and a thickness of 12 μm; and a polypropylene film (trade name:Taikoh FC, manufactured and sold by Futamura Chemical Industries Co.,Ltd., Japan) having a length of 18 cm, a width of 14 cm and a thicknessof 40 μm, were put one upon another in this order, wherein the sheetswere trued up on their respective one 18 cm-sides. The sheets wereadhered using a two-pack urethane adhesive to obtain a laminate. Thealuminum foil in the laminate was cut-out along the entire length of one18 cm-side by a depth (in a direction perpendicular to the peripheraledge) of 10 mm as measured from the peripheral edge of the laminate. Thelaminate was folded in two about a central line perpendicularlytraversing both 18 cm-sides thereof, thereby obtaining a folded laminatehaving a size of 9 cm×14 cm. With respect to each of three pairs of theopposite sides (i.e., a pair of opposite 9 cm-sides and two pairs ofopposite 14 cm-sides) of the folded laminate, the opposite sides weremelt-adhered to each other over a width of 10 mm from the peripheraledge thereof by heating at 180° C. for 8 seconds to thereby form ahermetic seal, thus providing a pouchy casing having an opening in theremaining pair of opposite 9 cm-sides and having terminal-withdrawalsites at the opening thereof.

An electrochemical cell prepared in substantially the same manner as inExample 1 was placed into the prepared pouchy casing and the terminalswere taken out is of the opening of the pouchy casing through theterminal-withdrawal sites. The opening of the pouchy casing washermetically sealed by heating at 180° C. for 8 seconds, therebyobtaining a battery. At the terminal-withdrawal sites of the pouchycasing, the width of the elongated, hermetic adhesion area was 20 mmfrom the peripheral edge of the pouchy casing. As mentioned above, thealuminum foil layer was cut-out along the entire length of 18 cm-side bya depth of 10 mm as measured from the peripheral edge of the pouchycasing. The depth of the cut-out portion was confirmed using a scalegraduated in 1 millimeters.

Ten batteries were prepared as described above. The prepared batterieswere subjected to charge/discharge cycle testing using acharge/discharge testing device (Model HJ-101SM6, manufactured and soldby Hokuto Denko Corporation, Japan. All of the ten batteries werecapable of standard charge/discharge operation and their averagedischarge capacity was 900 mAh. None of the batteries charged at aconstant voltage of 4.2 V suffered voltage-lowering and heat-generationcaused by short-circuiting even when the terminal were folded. Further,no leakage of liquid was observed.

In addition, a pouchy casing was prepared in substantially the samemanner as mentioned above, and 20 g of calcium chloride anhydride wassealed up inside the pouchy casing, instead of the electrochemical cell,in a width of 10 mm from the peripheral edge thereof by heating at 140°C. for 6 seconds. The sealed pouchy casing containing calcium chloridewas placed at a temperature of 60° C. and a relative humidity (RH) of90% for 3 months, but the increase in the weight of the pouchy casingwas less than 1 mg.

EXAMPLE 6

A laminate for producing a pouchy casing for a battery was prepared inthe following manner. Four different sheets respectively of apolyethylene terephthalate film (trade name: Melinex S, manufactured andsold by ICI Japan Ltd., Japan) having a length of 18 cm, a width of 14cm and a thickness of 12 μm; an aluminum foil having a length of 18 cm,a width of 14 cm and a thickness of 9 μm; an aromatic polyamide film(trade name: Aramica, manufactured and sold by Asahi Kasei KogyoKabushiki Kaisha, Japan) having a length of 18 cm, a width of 14 cm anda thickness of 25 μm; and a polypropylene film (trade name: Taikoh FC,manufactured and sold by Futamura Chemical Industries Co., Ltd., Japan)having a length of 18 cm, a width of 14 cm and a thickness of 40 μm,were put one upon another in this order, in which the sheets: wereadhered using a two-pack urethane adhesive to obtain a laminate. Withrespect to the aromatic polyamide film, the tension modulus and thecompression modulus of the film were 1,500 kg/mm² and 200 kg/mm²,respectively, as measured using a motor drive type universal testingmachine (trade name: DSS-500, manufactured and sold by ShimadzuCorporation, Japan).

The laminate was folded in two about a central line perpendicularlytraversing both 18 cm-sides thereof, thereby obtaining a folded laminatehaving a size of 9 cm×14 cm. With respect to each of two pairs ofopposite sides (i.e., a pair of opposite 9 cm-sides and a pair ofopposite 14 cm-sides) of the folded laminate, the opposite sides weremelt-adhered to each other over a width of 10 mm from the peripheraledge thereof by heating at 180° C. for 6 seconds to thereby form ahermetic seal, thus providing a pouchy casing having an opening in theremaining pair of opposite 9 cm-sides and having terminal-withdrawalsites at the opening thereof. An electrochemical cell prepared insubstantially the same manner as in Example 1 was placed into theprepared pouchy casing and the terminals were taken out of the openingof the pouchy casing through the terminal-withdrawal sites. The openingof the pouchy casing was hermetically sealed by heating at 180° C. for 6seconds. Before sealing up the electrochemical cell in the pouchycasing, the surface of the edge of the opening of the pouchy casing wastreated for electric insulation at portions thereof around theterminal-withdrawal sites. One surface of an aromatic polyamide film(trade name: Aramica, manufactured and sold by Asahi Kasei KogyoKabushiki Kaisha, Japan) (as an insulating material segment) having alength of 15 mm, a width of 5 mm and a thickness of 15 μm was coatedwith an epoxy resin adhesive (trade name: Cemedine EP-007, manufacturedand sold by Cemedine Co., Ltd., Japan). The adhesive-coated aromaticpolyamide film was folded in half with the adhesive-coated surface heldinside, and, as shown in FIGS. 4(a) and 4(b), adhered to the edge of theopening of the pouchy casing at portions thereof around theterminal-withdrawal sites, so that one half of the film was adhered tothe inner surface of the opening of the pouchy casing and the other halfof the film was adhered to the outer surface of the opening of thepouchy casing, thereby electrically insulating the peripheral edgethereof. At the terminal-withdrawal sites of the pouchy casing, thewidth of the elongated, hermetic adhesion area was 10 mm from theperipheral edge of the pouchy casing, and the electrically insulatingmaterial segment was adhered so as to cover an area of a width (in adirection parallel to the peripheral edge) of 15 mm and a depth (in adirection perpendicular to the peripheral edge) of 2.5 mm.

Five batteries were prepared as described above. The prepared batterieswere subjected to charge/discharge cycle testing using acharge/discharge testing device (Model HJ-101SM6, manufactured and soldby Hokuto Denko Corporation, Japan). All of the five batteries werecapable of standard charge/discharge operation and their averagedischarge capacity was 900 mAh. None of the batteries charged at aconstant voltage of 4.2 V suffered voltage-lowering or heat-generationcaused by short-circuiting even when the terminals were folded. Further,no leakage of liquid was observed.

In addition, a pouchy casing was prepared in substantially the samemanner as mentioned above, and 20 g of calcium chloride anhydride wassealed up inside the pouchy casing, instead of the electrochemical cell.The sealed pouchy casing containing calcium chloride was placed at atemperature of 60° C. and a relative humidity (RH) of 90° C. for 3months, but the increase in the weight of the pouchy casing was lessthan 1 mg.

EXAMPLE 7

A laminate was prepared in the following manner. Four different sheetsrespectively of a polyethylene terephthalate film (trade name: MelinexS, manufactured and sold by ICI Japan Ltd., Japan) having a length of 18cm, a width of 14 cm and a thickness of 12 μm; an aluminum foil having alength of 18 cm, a width of 14 cm and a thickness of 9 μm; apolyethylene terephthalate film (trade name: Melinex S, manufactured andsold by ICI Japan Ltd., Japan) having a length of 18 cm, a width of 14cm and a thickness of 12 μm; and a polypropylene film (trade name:Taikoh FC, manufactured and sold by Futamura Chemical Industries Co.,Ltd., Japan) having a length of 18 cm, a width of 14 cm and a thicknessof 40 μm, were put one upon another in this order, in which the sheetswere adhered using a two-pack urethane adhesive to obtain a laminate.With respect to the polyethylene terephthalate film, the tension moduluswas 400 kg/mm², as measured using a motor drive type universal testingmachine (trade name: DSS-500, manufactured and sold by ShimadzuCorporation, Japan).

The laminate was folded in two about a central line perpendicularlytraversing both 18 cm-sides thereof, thereby obtaining a folded laminatehaving a size of 9 cm×14 cm. With respect to each of two pairs ofopposite sides (i.e., a pair of opposite 9 cm-sides and a pair ofopposite 14 cm-sides) of the folded laminate, the opposite sides weremelt-adhered to each other over a width of 10 mm from the peripheraledge thereof by heating at 180° C. for 6 seconds to thereby form ahermetic seal, thus providing a pouchy casing having an opening in theremaining pair of opposite 9 cm-sides and having terminal-withdrawalsites at the opening thereof. The surface of the edge of the opening ofthe pouchy casing was treated for electric insulation at portionsthereof around the terminal-withdrawal sites. A mixture of anamide-imide ester varnish (trade name: Nitron V-800, manufactured andsold by Nitto Denko Corp., Japan) and a hardner (No. 5 attached to thevarnish) (as an electrically insulating material) was applied onto thesurface of the edge of the opening of the pouchy casing around theterminal-withdrawal sites, and placed at 100° C. for 15 minutes, therebyelectrically insulating the peripheral edge thereof. An electrochemicalcell prepared in substantially the same manner as in Example 1 wasplaced into the prepared pouchy casing and the terminals were taken outof the opening of the pouchy casing through the terminal-withdrawalsites. The opening of the pouchy casing was hermetically sealed byheating at 180° C. for 6 seconds. At the terminal-withdrawal sites ofthe pouchy casing, the width of the elongated, hermetic adhesion areawas 20 mm from the peripheral edge of the pouchy casing, and the entirelength of the 18 cm-side of the pouchy casing was coated with theelectrically insulating material by a depth (in a directionperpendicular to the peripheral edge of the pouchy casing) of 5 mm fromthe peripheral edge thereof.

Five batteries were prepared as described above. The prepared batterieswere subjected to charge/discharge cycle testing using acharge/discharge testing device (Model HJ-101SM6, manufactured and soldby Hokuto Denko Corporation, Japan). All of the five batteries werecapable of standard charge/discharge operation and their averagedischarge capacity was 900 mAh. None of the batteries charged at aconstant voltage of 4.2 V suffered voltage-lowering and heat-generationcaused by short-circuiting even when the terminals were folded. Further,no leakage of liquid was observed.

In addition, a pouchy casing was prepared in substantially the samemanner as mentioned above, and 20 g of calcium chloride anhydride wassealed up inside the pouchy casing, instead of the electrochemical cell.The sealed pouchy casing containing calcium chloride was placed at atemperature of 60° C. and a relative humidity (RH) of 90% for 3 months,but the increase in the weight of the pouchy casing was less than 1 mg.

EXAMPLE 8

A laminate was prepared in the following manner. Four different sheetsrespectively of an aromatic polyamide film (trade name: Aramica,manufactured and sold by Asahi Kasei Kogyo Kabushiki Kaisha, Japan)having a length of 18 cm, a width of 14 cm and a thickness of 25 μm; analuminum foil having a length of 18 cm, a width of 13 cm and a thicknessof 25 μm; an aromatic polyamide film (trade name: Aramica, manufacturedand sold by Asahi Kasei Kogyo Kabushiki Kaisha, Japan) having a lengthof 18 cm, a width of 14 cm and a thickness of 25 μm; and a polypropylenefilm (trade name: Taikoh FC, manufactured and sold by Futamura ChemicalIndustries Co., Ltd., Japan) having a length of 18 cm, a width of 14 cmand a thickness of 40 μm, were put one upon another in this order,wherein the sheets were trued up on their respective one 18 cm-sides.The sheets were adhered using a two-pack urethane adhesive to obtain alaminate. With respect to the aromatic polyamide film used in thelaminate, the aromatic polyamide film exhibited no melting temperatureas measured by DSC method. The aluminum foil in the laminate wasdeficient along the entire length of one 18 cm-side of the foil by adepth (in a direction perpendicular to the peripheral edge of the foil)of 10 mm from the peripheral edge of the laminate. The laminate wasfolded in two about a central line perpendicularly traversing both 18cm-sides, thereby obtaining a folded laminate having a size of 9 cm×14cm. With respect to each of two pairs of opposite sides (i.e., a pair ofopposite 9 cm-sides free of a deficient portion and a pair of opposite14 cm-sides) of the folded laminate, the opposite sides weremelt-adhered to each other over a width of 10 mm from the peripheraledge thereof by heating at 180° C. for 6 seconds to thereby form ahermetic seal, thus providing a pouchy casing having an opening in theremaining pair of opposite 9 cm-sides and having terminal-withdrawalsites at the opening thereof. An electrochemical cell prepared insubstantially the same manner as in Example 1 was placed into theprepared pouchy casing and the terminals were taken out of the openingof the pouchy casing through the terminal-withdrawal sites. The openingof the pouchy casing was hermetically sealed by heating at 180° C. for 6seconds, thereby obtaining a battery. At the terminal-withdrawal sitesof the pouchy casing, the width of the elongated, hermetic adhesion areawas 20 mm from the peripheral edge of the pouchy casing. As mentionedabove, the aluminum foil layer was cut-out along the entire length ofthe 18 cm-side of the foil by a depth of 10 mm as measured from theperipheral edge of the pouchy casing. The depth of the cut-out portionwas confirmed using a scale graduated in 1 millimeters.

Five batteries were prepared as described above. All of the fivebatteries were capable of standard charge/discharge operation and theiraverage discharge capacity was 900 mAh.

When a battery having a capacity of 910 mAh was charged at a constantvoltage of 4.2 V and was placed in an oven (250° C.), gas effused fromthe adhesion area between the terminals and the laminate of the pouchycasing, but the laminate did not catch fire. In addition, when a batteryhaving a capacity of 880 mAh was subjected to a charging operation at aconstant current of 1.8 A, gas effusion was observed, but the laminatedid not catch fire.

EXAMPLE 9

A laminate was prepared in the following manner. Four different sheetsrespectively of a polyphenylene sulfide film (trade name: Torelina,manufactured and sold by Toray Industries Inc., Japan) having a lengthof 18 cm, a width of 14 cm and a thickness of 25 μm; an aluminum foilhaving a length of 18 cm, a width of 14 cm and a thickness of 25 μm; apolyphenylene sulfide film having a length of 18 cm, a width of 14 cmand a thickness of 25 μm; and a polyethylene-vinyl alcohol copolymerfilm (trade name: Eval, manufactured and sold by Kuraray Co., Ltd.,Japan) having a length of 18 cm, a width of 14 cm and a thickness of 20μm, were put one upon another in this order, in which the sheets wereadhered using a two-pack urethane.adhesive to obtain a laminate. Themelting temperature of the polyphenylene sulfide film used in thelaminate is 285° C. as measured by DSC method. The laminate was foldedin two about a central line perpendicularly traversing both 18 cm-sidesthereof, thereby obtaining a folded laminate having a size of 9 cm×14cm. With respect to each of three pairs of opposite sides (i.e., a pairof opposite 9 cm-sides and two pairs of opposite 14 cm-sides) of thefolded laminate, the opposite sides were melt-adhered to each other overa width of 10 mm from the peripheral edge thereof by heating at 180° C.for 6 seconds to thereby form a hermetic seal, thus providing a pouchycasing having an opening in the remaining pair of opposite 9 cm-sidesand having terminal-withdrawal sites at the opening thereof. Anelectrochemical cell prepared in substantially the same manner as inExample 1 was placed into the prepared pouchy casing and the terminalswere taken out of the opening of the pouchy casing through theterminal-withdrawal sites. The opening of the pouchy casing washermetically sealed by heating at 180° C. for 6 seconds, therebyobtaining a battery. After sealing up the electrochemical cell in thepouchy casing, the surface of the edge of the opening of the pouchycasing was treated in the following manner for electrical insulation atportions thereof around the terminal withdrawal sites. A polyimideadhesive tape (Kapton adhesive tape manufactured and sold by TeraokaSeisakusho Co., Ltd., Japan) (as an electrically insulating materialsegment) was adhered to the edge of the opening of the pouchy casing atportions thereof around the terminal-withdrawal sites. At theterminal-withdrawal sites of the pouchy casing, the width of theelongated, hermetic adhesion area was 10 mm from the peripheral edge ofthe pouchy casing, and the electrically insulating material segment wasadhered so as to cover an area of a width (in a direction parallel tothe peripheral edge) of 40 mm and a depth (in a direction perpendicularto the peripheral edge) of 2.5 mm.

Ten batteries were prepared as described above. All of the ten batterieswere capable of standard charge/discharge operation and their averagedischarge capacity was 900 mAh. None of the batteries charged at aconstant voltage of 4.2 V suffered voltage-lowering and heat-generationcaused by short-circuiting even when the terminals were folded. Further,no leakage of liquid was observed.

In addition, a pouchy casing was prepared in substantially the samemanner as mentioned above, and 20 g of calcium chloride anhydride wassealed up inside the pouchy casing, instead of the electrochemical cell.The sealed pouchy casing containing calcium chloride was placed at atemperature of 60° C. and a relative humidity (RH) of 90% for 3 months,but the increase in the weight of the pouchy casing was less than 1 mg.

Further, when a battery having a capacity of 905 mAh was charged at aconstant voltage of 4.2 V and was placed in an oven (250° C.), gaseffused from the adhesion area between the terminals and the laminate ofthe pouchy casing, but the laminate did not catch fire. In addition,when a battery having a capacity of 850 mAh was subjected to a chargingoperation at a constant current of 1.8 A, gas effusion was observed, butthe laminate did not catch fire.

EXAMPLE 10

A laminate was prepared in the following manner. Four different sheetsrespectively of a polyvinyl alcohol film (trade name: Kuraray VinylonFilm, manufactured and sold by Kuraray Co., Ltd., Japan) having a lengthof 18 cm, a width of 14 cm and a thickness of 25 μm; an aluminum foilhaving a length of 18 cm, a width of 13 cm and a thickness of 25 μm; apolyether ether ketone film (trade name: TALPA-2000, manufactured andsold by Mitsui Toatsu Chemical, Inc., Japan) having a length of 18 cm, awidth of 14 cm and a thickness of 25 μm; and a polypropylene film (tradename: Taikoh FC, manufactured and sold by Futamura Chemical IndustriesCo., Ltd., Japan) having a length of 18 cm, a width of 14 cm and athickness of 40 μm, were put one upon another in this order, wherein thesheets were trued up on their respective one 18 cm-sides. The sheetswere adhered using a two-pack urethane adhesive to obtain a laminate.The melting temperature of the polyether ether ketone film and thepolyvinyl alcohol film used in the laminate, as measured by DSC method,were respectively 334° C. and 230° C. The aluminum foil in the laminatewas deficient along the entire length of one 18 cm-side of the foil by adepth (in a direction perpendicular to the peripheral edge of the foil)of 10 mm from the peripheral edge of the laminate. The laminate wasfolded in two about a central line perpendicularly traversing both 18cm-sides thereof, thereby obtaining a folded laminate having a size of 9cm×14 cm. With respect to each of three pairs of opposite sides (i.e., apair of opposite 9 cm-sides free of a deficient portion and two pairs ofopposite 14 cm-sides) of the folded laminate, the opposite sides weremelt-adhered to each other over a width of 10 mm from the peripheraledge thereof by heating at 180° C. for 6 seconds to thereby form ahermetic seal, thus providing a pouchy casing having an opening in theremaining pair of opposite 9 cm-sides and having terminal-withdrawalsites at the opening thereof. An electrochemical cell prepared insubstantially the same manner as in Example 1 was placed into theprepared pouchy casing and the terminals were taken out of the openingof the pouchy casing through the terminal-withdrawal sites. The openingof the pouchy casing was hermetically sealed by heating at 180° C. for 6seconds, thereby obtaining a battery. At the terminal-withdrawal sitesof the pouchy casing, the width of the elongated, hermetic adhesion areawas 20 mm from the peripheral edge of the pouchy casing. As mentionedabove, the aluminum foil layer was cut-out along the entire length ofthe 18 cm-side of the foil by a depth of 10 mm as measured from theperipheral edge of the pouchy casing. The depth of the cut-out portionwas confirmed using a scale graduated in 1 millimeters.

Five batteries were prepared as described above. All of the fivebatteries were capable of standard charge/discharge operation and theiraverage discharge capacity was 900 mAh. None of the batteries charged ata constant voltage of 4.2 V suffered voltage-lowering andheat-generation caused by short-circuiting even when the terminals werefolded. Further, no leakage of liquid was observed.

In addition, a pouchy casing was prepared in substantially the samemanner as mentioned above, and 20 g of calcium chloride anhydride wassealed up inside the pouchy casing, instead of the electrochemical cell.The sealed pouchy casing containing calcium chloride was placed at atemperature of 60° C. and a relative humidity (RH) of 90% for 3 months,but the increase in the weight of the pouchy casing was less than 1 mg.

Further, when a battery having a capacity of 905 mAh was charged at aconstant voltage of 4.2 V and was placed in an oven (250° C.), gaseffused from the adhesion area between the terminals and the laminate ofthe pouchy casing, but the laminate did not catch fire.

EXAMPLE 11

A battery was prepared in substantially the same manner as mentioned inExample 8, except that a laminate for producing the pouchy casing wasprepared in the following manner. Four different sheets respectively ofa polyimide film (trade name: Kapton, manufactured and sold by DuPont-Toray Co., Ltd., Japan) having a length of 18 cm, a width of 14 cmand a thickness of 12.5 μm; an aluminum foil having a length of 18 cm, awidth of 13 cm and a thickness of 20 μm; a polyphenylene sulfide filmhaving a length of 18 cm, a width of 14 cm and a thickness 25 μm; and apolypropylene film (trade name: Taikoh FC, manufactured and sold byFutamura Chemical Industries Co., Ltd., Japan) having a length of 18 cm,a width of 14 cm and a thickness of 60 μm, were put one upon another inthis order, wherein the sheets were trued up on their respective one 18cm-sides. The sheets were adhered using a two-pack urethane adhesive toobtain a laminate. (With respect to the polyimide film used in thelaminate, the polyimide film exhibited no melting temperature asmeasured by DSC method.)

The prepared battery exhibited excellent properties which wereequivalent to those of the battery prepared in Example 8.

EXAMPLE 12

The positive electrode sheet (having the positive electrode layer on oneside thereof) prepared in the same manner as mentioned in Example 1 wasfabricated so as to have a size of 6 cm×50 cm. The negative electrodesheet (having the negative electrode layer on one side thereof) preparedin the same manner as mentioned in Example 1 was fabricated so as tohave a size of 6.5 cm×51 cm. A polyethylene separator (trade name:Hipore U-2, manufactured and sold by Asahi Kasei Kogyo Kabushiki Kaisha,Japan) was fabricated so as to have a size of 7 cm×54 cm. Then, theobtained positive electrode sheet, the separator and the negativeelectrode sheet were laminated so that the separator was interposedbetween the two types of electrode sheets, and the positive electrodelayer of the positive electrode sheet and the negative electrode layerof the negative electrode sheet were opposite to each other through theseparator, thereby obtaining a positive electrode/separator/negativeelectrode laminate. The obtained positive electrode/separator/negativeelectrode laminate was immersed in a non-aqueous electrolytic solutionobtained by dissolving lithium tetrafluoroborate (LiBF₄) in a mixedsolution of ethylene carbonate (EC), propylene carbonate (PC) andγ-butyrolactone (γ-BL) (EC/PC/γ-BL weight ratio=1:1:2, and LiBF₄concentration: 1.5 mol/liter) to thereby impregnate the separator withthe electrolytic solution. An roughened aluminum foil having a length of10 cm, a width of 1 cm, and a thickness of 50 μm (Ra=0.4 μm and TIR=2.8μm) as a positive terminal, and a roughened copper foil having a lengthof 10 cm, a width of 1 cm and a thickness of 35 μm (Ra=1.2 μm andTIR=6.5 μm) as a negative terminal were respectively connected to thecurrent collectors of the positive and negative electrode sheets (whichare both outermost layers of the positive electrode/separator/negativeelectrode laminate) by means of an ultrasonic metal welder. Theterminals were, respectively, connected to the current collectors sothat one end of the width of the terminal was positioned at a distanceof 1 cm from one end of the width of the electrode sheet. Next, thepositive electrode/separator/negative electrode laminate with theterminals were accordion folded at intervals so as to have five folds,thereby obtaining an electrochemical cell.

Using the above-obtained electrochemical cell and a laminate prepared insubstantially the same manner as mentioned in Example 5, a battery wasprepared in substantially the same manner as mentioned in Example 5.

No leakage of liquid was observed in the above-prepared battery. Theprepared battery was subjected to charge/discharge cycle testing using acharge/discharge testing device (Model HJ-101SM6, manufactured and soldby Hokuto Denko Corporation, Japan). The battery was capable of standardcharge/discharge operation and their average discharge capacity was 900mAh.

In addition, no leakage of liquid was observed from the hermetic seal ofthe pouchy casing even when the battery was placed at a temperature of95° C. for 48 hours or at room temperature for 1 month or more.

EXAMPLE 13

A laminate (14 cm×18 cm) for producing a pouchy casing for a battery wasprepared in substantially the same manner as mentioned in Example 11. Inthe laminate, the aluminum foil was cut-out along the entire length ofone 18 cm-side of the foil by a depth (in a direction perpendicular tothe peripheral edge of the foil) of 10 mm as measured from theperipheral edge of the laminate. The laminate was folded in two about acentral line perpendicularly traversing both 18 cm-sides thereof,thereby obtaining a folded laminate having a size of 9 cm×14 cm. Withrespect to each of three pairs of opposite sides (i.e., a pair ofopposite 9 cm-sides free of a cut-out portion and two pairs of opposite14 cm-sides) of the folded laminate, the opposite sides weremelt-adhered to each other over a width of 10 mm from the peripheraledge thereof by heating at 180° C. for 6 seconds to thereby form ahermetic seal, thus providing a pouchy casing having an opening in theremaining pair of opposite 9 cm-sides and having terminal-withdrawalsites in the peripheral edge of the opening thereof. Prior to the meltadhesion, an elongated SUS foil having a length of 15 mm, a width of 5mm and a thickness of 10 μm was interposed between the opposing sides ofthe laminate (i.e., the polypropylene film layers), so that, after theopposite inner thermoplastic layers were melt-adhered to each other atan elongated, hermetic adhesion area, the elongated SUS foil penetratedthrough and across the elongated, hermetic adhesion area, wherein bothends of the elongated SUS foil were outside of both sides of theelongated, hermetic adhesion area. Thus, a safety valve was provided. Anelectrochemical cell was prepared in substantially the same manner as inExample 1 except that the terminals were prepared as follows. Forpreparing a positive terminal, a roughened aluminum foil (Ra 0.4 μm andTIR=2.8 μm) having a thickness of 50 μm was fabricated into a piecehaving a length of 3 cm and a width of 10 mm, and another piece having alength of 8 cm and a width of 10 mm. The above-mentioned two aluminumpieces were arranged so as to overlap at their respective one endportions over lengths of 1 cm, and the overlapping portions were adheredusing an electrically conductive adhesive double-coated tape (tradename: WMFT, manufactured and sold by Teraoka Seisakusho Co.,Ltd.,.Japan) having a size of 1 cm×1 cm. Then, the adhered portion ofthe aluminum pieces was heat-pressed at 185° C. for 5 seconds to therebyobtain an aluminum terminal having a length of 10 cm (the resistancebetween both ends of the terminal was 10 mΩ). The obtained aluminumterminal was used as a positive terminal. As a negative terminal, aroughened copper foil (Ra=1.2 μm and TIR=6.5 μm) having a length of 10cm, a width of 1 cm and a thickness of 35 μm was used. Both terminalswere, respectively, connected to the current collectors of the positiveand negative electrode sheets, which were both outermost layers of thepositive electrode/electrolyte/negative electrode laminate, by means ofan ultrasonic metal welder (trade name: SW-200Z38S, manufactured andsold by Ultrasonic Engineering Co., Ltd. Japan), wherein theweld-connection of the terminals to the current collectors was effectedover a length of 1 cm from the respective edges of the currentcollectors. The thus obtained electrochemical cell was placed into thepouchy casing prepared above and the terminals were taken out of theopening of the pouchy casing through the terminal-withdrawal sites. Theopening of the pouchy casing was hermetically sealed by heating at 180°C. for 6 seconds, thereby preparing a battery.

Five batteries were prepared as described above. At theterminal-withdrawal sites of the pouchy casing, the width of thehermetic adhesion area was 20 mm from the peripheral edge of the pouchycasing, and the aluminum foil layer was cut-out along the entire lengthof the peripheral edge of the foil by a depth of 10 mm as measured fromthe peripheral edge of the pouchy casing. The depth of the cut-outportion was confirmed under an optical microscope (System MetalMicroscope BHT, manufactured and sold by Olympus Optical Co., Ltd.,Japan) using an objective micrometer graduated in 0.01 millimeters(manufactured and sold by Olympus Optical Co., Ltd., Japan). Due to theweak adhesion between the elongated SUS foil and the polypropylene film,the elongated SUS foil interposed between the opposing sides of thelaminate was capable of functioning as a safety valve for the battery.The prepared batteries were subjected to charge/discharge cycle testingusing a charge/discharge testing device (Model HJ-101SM6, manufacturedand sold by Hokuto Denko Corporation, Japan). All of the five batterieswere capable of standard charge/discharge operation and their averagedischarge capacity was 900 mAh. The battery was subjected to a chargingoperation at a constant capacity of 900 mA, and even after 3 hours ofcharging operation, the expansion of the battery was small and thethickness of the battery became only 1.5 times that of the batterybefore subjecting to the charging operation. In addition, the batterydid not suffer bursting and catch fire.

EXAMPLE 14

A laminate (14 cm×18 cm) for producing a pouchy casing for a battery wasprepared in substantially the same manner as mentioned in Example 5.

A copper foil (as a terminal) having a width of 1 cm, a length of 4 cmand a thickness of 35 μm was prepared, and the surface thereof wasroughened (Ra=1.2 μm and TIR=6.5 μm). The roughened copper foil (as anegative terminal for the below-mentioned pouchy casing). was placed onthe polypropylene film layer (inner thermoplastic resin layer) of thelaminate on the 18 cm-side of the laminate at a portion which is 2 cmdistant from the central line (folding line) perpendicularly traversingboth 18 cm-sides of the laminate, and a portion of the copper foil whichwas 2.5 cm from the inner edge of the copper foil was adhered, by resinmelting, to the polypropylene film of the laminate by heating at 180° C.for 6 seconds, and the remaining 1.5 cm portion of the copper foilprotruded from the peripheral edge of the laminate. Then, a polyimideadhsive tape (Kapton adhesive tape manufactured and sold by TeraokaSeisakusyo Co., Ltd., Japan) having a width of 1 cm was adhered onto theinner thermoplastic resin layer of the laminate along the entire lengthof the 18 cm-side so that the outer edge of the tape was parallel to andwas positioned at a distance 1.5 cm from the peripheral edge of thelaminate. A portion of the adhered tape which was overlapping the copperfoil terminal and both end portions (1 cm-long) of the adhered tape wereremoved from the inner thermoplastic resin layer of the laminate.

An electrochemical cell was prepared in substantially the same manner asmentioned in Example 1 except that a roughened copper foil (Ra=1.2 μm,TIR=6.5 μm) was used as a negative terminal. A part of the negativeterminal connected to the negative current collector of theelectrochemical cell was cut-away so that the length of the negativeterminal protruding outside of the electrochemical cell was 1.5 cm. Theresultant electrochemical cell was placed on the inner thermoplasticresin layer of the laminate so as for the negative terminal of theelectrochemical cell to partially overlap the above-mentioned coppernegative terminal (for the pouchy casing) attached onto the innerthermoplastic resin layer of the laminate, wherein the forward endportion of the former (terminal) overlapped the rear end portion of thelatter (terminal) over a length of 1 cm. The negative terminal of theelectrochemical cell and the copper terminal for the below-mentionedmentioned pouchy casing were connected by means of an ultrasonic metalwelder (USW-200Z38S, manufactured and sold by Ultrasonic EngineeringCo., Ltd., Japan) by applying a load of 3 kg for 0.1 seconds to theoverlapping portion thereof at an area of 2.5 mm×5 mm. The resultantlaminate was folded in two about the central line perpendicularlytraversing both 18 cm-sides thereof, thereby obtaining a folded laminatehaving a size of 9 cm×14 cm so as to enclose the electrochemical celltherein. With respect to each of the three pairs of opposite sides(i.e., a pair of opposite 9 cm-sides without the terminals and two pairsof opposite 14 cm-sides), the opposite sides were melt-adhered to eachother over a width of 10 mm from the peripheral edge of the laminate byheating at 180° C. for 6 seconds to form a hermetic seal, therebyforming a pouchy casing containing the electrochemical cell. Withrespect to the remaining 9 cm-side with the terminals (including thecopper negative terminal for the pouchy casing and the positiveterminal) protruding therefrom, the pair of opposite sides weremelt-adhered to each other over a width of 25 mm from the peripheraledge of the laminate by heating at 180° C. for 6 seconds to thereby forma hermetic seal. As a result, the electrochemical cell was sealed upinside the pouchy casing to obtain a battery.

Five batteries were prepared in the same manner as described above. Inthe obtained battery, the Kapton adhesive tape and the polypropylenelayer of the laminate were not melt-adhered to each other. The negativeterminal protruding from the electrochemical cell was adhered to one ofthe inner surfaces of the pouchy casing by resin melting, while thecopper terminal protruding from the pouchy casing was adhered, by resinmelting, to the other inner surface of the pouchy casing which wasopposing the inner surface to which the negative terminal of theelectrochemical cell was adhered by resin melting. The preparedbatteries were subjected to charge/discharge cycle testing using acharge/discharge testing device (Model HJ-101SM6, manufactured and soldby Hokuto Denko Corporation, Japan).

All of the five batteries were capable of standard charge/dischargeoperation and their average discharge capacity was 900 mAh. The batterywas subjected to charging operation at a constant current of 900 mA, and2.5 hours after the start of the charging operation, the pouchy casingwas caused to expand to a thickness of twice that of the battery beforesubjecting the battery to the charging operation, and the ultrasonicweld-connection between the negative terminal and the copper terminalwas broken. Consequently, the electric current was cut-off and thebattery was no longer. charged. In addition, the battery did not sufferbursting and catch fire.

Comparative Example 1

A laminate was prepared in the following manner. Four different sheetsrespectively of a polyethylene terephthalate film (trade name: MelinexS, manufactured and sold by ICI Japan Ltd., Japan) (as an outerelectrically insulating material layer) having a length of 18 cm, awidth of 14 cm and a thickness of 12 μm; an aluminum foil (as a middlemetal foil layer) having a length of 18 cm, a width of 14 cm and athickness of 9 μm; a polyethylene terephthalate film (trade name:Melinex S, manufactured and sold by ICI Japan Ltd., Japan) (as anintermediate electrically insulating material layer) having a length of18 cm, a width of 14 cm and a thickness of 12 μm; and a polypropylenefilm (trade name: Taikoh FC,. manufactured and sold by Futamura ChemicalIndustries Co., Ltd., Japan) (as an inner thermoplastic resin layer)having a length of 18 cm, a width of 14 cm and a thickness of 40 μm,were put one upon another in this order, in which the sheets wereadhered using a two-pack urethane adhesive to obtain a laminate. In theobtained laminate, the aluminum foil layer was exposed at the peripheraledge thereof. The laminate was folded in two about a central lineperpendicularly traversing both 18 cm-sides thereof, thereby obtaining afolded laminate having a size of 9 cm×14 cm. With respect to each ofthree pairs of opposite sides (i.e., a pair of opposite 9 cm-sides andtwo pairs of opposite 14 cm-sides) of the folded laminate, the oppositesides were melt-adhered to each other over a width of 10 mm from theperipheral edge of the laminate by heating.at 180° C. for 6 seconds tothereby form a hermetic seal, thus providing a pouchy casing having anopening in the remaining pair of opposite 9 cm-sides and havingterminal-withdrawal sites at the opening thereof. The peripheral portionof the opening of the pouchy casing was cut-away by a depth (in adirection perpendicular to the peripheral edge thereof) of 1 mm tothereby true up the edges of all four layers (i.e., the thermoplasticresin layer, the metal foil layer, and the electrically insulatingmaterial layers) of the laminate. An electrochemical cell prepared insubstantially the same manner as in Example 1 was placed into theprepared pouchy casing and the terminals were taken out of the openingof the pouchy casing through the terminal-withdrawal sites. The openingof the pouchy casing was hermetically sealed by heating at 180° C. for 6seconds, thereby obtaining a battery.

Five batteries were prepared in the same manner as described above. Atthe terminal-withdrawal sites of the pouchy casing, the width of theelongated, hermetic adhesion area was 20 mm from the peripheral edge ofthe pouchy casing. When the boundary between the terminals and thepouchy casing was observed under an optical microscope (System MetalMicroscope BHT, manufactured and sold by Olympus Optical Co., Ltd.,Japan) using an objective micrometer graduated in 0.01 millimeters(manufactured and sold by Olympus Optical Co., Ltd., Japan), it wasfound that the polypropylene resin was melt-protruding from theperipheral edge of the pouchy casing at a width of 0.05 mm.

The prepared batteries were subjected to charge/discharge cycle testingusing a charge/discharge testing device (Model HJ-101 SM6, manufacturedand sold by Hokuto Denko Corporation, Japan) while paying special carenot to fold the terminals. All of the five batteries were capable ofstandard charge/discharge operation, but the batteries charged at aconstant voltage of 4.2 V suffered voltage-lowering and heat-generationcaused by short-circuiting when the terminals were folded. Theresistance between the folded terminals was 2 MΩ.

In addition, a pouchy casing was prepared in substantially the samemanner as mentioned above, and 20 g of calcium chloride anhydride wassealed up inside the pouchy casing, instead of the electrochemical cell.The sealed pouchy casing containing calcium chloride was placed at atemperature of 60° C. and a relative humidity (RH) of 90% for 3 months,but the increase in the weight of the pouchy casing was less than 1 mg.

Comparative Example 2

A laminate was prepared in the following manner. Four different sheetsrespectively of a polyethylene terephthalate film (trade name: MelinexS, manufactured and sold by ICI Japan Ltd., Japan) (as an outerelectrically insulating material layer) having a length of 18 cm, awidth of 14 cm and a thickness of 25 μm; an aluminum foil (as a middlemetal foil layer) having a length of 18 cm, a width of 14 cm and athickness of 12 μm; a stretched nylon film (trade name: Unilon,manufactured and sold by Idemitsu Petrochemical Co., Ltd., Japan) (as anintermediate electrically insulating material layer) having a length of18 cm, a width of 14 cm and a thickness of 15 μm; and an L-LDPE film(trade name: LS-700C, manufactured and sold by Idemitsu PetrochemicalCo., Ltd., Japan) (as an inner thermoplastic resin layer) having alength of 18 cm, a width of 13 cm and a thickness of 50 μm, were put oneupon another in this order, in which the sheets were adhered using atwo-pack urethane adhesive to obtain a laminate. In the obtainedlaminate, the aluminum foil layer was exposed at the peripheral edgethereof. The laminate was folded in two about a central lineperpendicularly traversing both 18 cm-sides thereof, thereby obtaining afolded laminate having a size of 9 cm×14 cm. With respect to each ofthree pairs of opposite sides (i.e., a pair of opposite 9 cm-sides andtwo pairs of opposite 14 cm-sides) of the folded laminate, the oppositesides were melt-adhered to each other over a width of 10 mm from theperipheral edge thereof by heating at 140° C. for 6 seconds to therebyform a hermetic seal, thus providing a pouchy casing having an openingin the remaining pair of opposite 9 cm-sides and havingterminal-withdrawal sites at the opening thereof. The peripheral portionof the opening of the pouchy casing was cut-away by a depth (in adirection perpendicular to the peripheral edge thereof) of 1 mm tothereby true up the edges of all four layers (i.e., the thermoplasticresin layer, the metal foil layer, and the electrically insulatingmaterial layers) of the laminate. An electrochemical cell prepared insubstantially the same manner as in Example 1 was placed into theprepared pouchy casing and the terminals were taken out of the openingof the pouchy casing through the terminal-withdrawal sites. The openingof the pouchy casing was hermetically sealed by heating at 120° C. for 6seconds, thereby obtaining a battery. At the terminal-withdrawal sitesof the pouchy casing, the width of the elongated, hermetic adhesion areawas 20 mm from the peripheral edge of the pouchy casing.

Five batteries were prepared in the same manner as described above. Whenthe peripheral edge of the battery at a portion thereof from which theterminal protruded was observed under an optical microscope (SystemMetal Microscope BHT, manufactured and sold by Olympus Optical Co.,Ltd., Japan) using an objective micrometer graduated in 0.01 millimeters(manufactured and sold by Olympus Optical Co., Ltd., Japan), it wasfound that the L-LDPE resin was melt-protruding from the peripheral edgeof the pouchy casing at a width of 0.07 mm.

The prepared batteries were subjected to charge/discharge cycle testingusing a charge/discharge testing device (Model HJ-101SM6, manufacturedand sold by Hokuto Denko Corporation, Japan) while paying special carenot to fold the terminals. All of the five batteries were capable ofstandard charge/discharge operation, but the batteries charged at aconstant voltage of 4.2 V suffered voltage-lowering and heat-generationcaused by short-circuiting when the terminals were folded. Theresistance between the folded terminals was 100 MΩ.

In addition, a pouchy casing was prepared in substantially the samemanner as mentioned above, and 20 g of calcium chloride anhydride wassealed up inside the pouchy casing, instead of the electrochemical cell.The sealed pouchy casing containing calcium chloride was placed at atemperature of 60° C. and a relative humidity (RH) of 90% for 3 months,but the increase in the weight of the pouchy casing was less than 1 mg.

Comparative Example 3

A laminate was prepared in the following manner. Four different sheetsrespectively of a polyethylene terephthalate film (trade name: MelinexS, manufactured and sold by ICI Japan Ltd., Japan) (as an outerelectrically insulating material layer) having a length of 18 cm, awidth of 14 cm and a thickness of 12 μm; an aluminum foil (as a middlemetal foil layer) having a length of 18 cm, a width of 11.8 cm and athickness of 9 μm; a polyethylene terephthalate film (trade name:Melinex S, manufactured and sold by ICI Japan Ltd., Japan) (as anintermediate electrically insulating material layer) having a length of18 cm, a width of 14 cm and a thickness of 12 μm; and a polypropylenefilm (trade name: Taikoh FC, manufactured and sold by Futamura ChemicalIndustries Co., Ltd., Japan) (as an inner thermoplastic resin layer)having a length of 18 cm, a width of 14 cm and a thickness of 40 μm,were put one upon another in this order, wherein the sheets were truedup on their respective one 18 cm-sides. The sheets were adhered using atwo-pack urethane adhesive to obtain a laminate. The aluminum foil wascut-out along the entire length of one 18 cm-side of the foil by a depth(in a direction perpendicular to the peripheral edge of the foil) of 22mm as measured from the peripheral edge of the laminate. The laminatewas folded in two about a central line perpendicularly traversing both18 cm-sides thereof, thereby obtaining a folded laminate having a sizeof 9 cm×14 cm. With respect to each of three pairs of opposite sides(i.e., a pair of opposite 9 cm-sides free of a cut-out portion and twopairs of opposite 14 cm-sides) of the folded laminate, the oppositesides were melt-adhered to each other over a width of 10 mm from theperipheral edge thereof by heating at 180° C. for 6 seconds to therebyform a hermetic seal, thus providing a pouchy casing having an openingin the remaining pair of opposite 9 cm-sides and havingterminal-withdrawal sites at the. opening thereof.

20 g of calcium chloride anhydride was sealed up inside the pouchycasing by hermetically sealing the opening of the pouchy casing. At aportion of the pouchy casing which corresponds to theterminal-withdrawal sites, the width of the elongated, hermetic adhesionarea was 20 mm from the peripheral edge of the pouchy casing. Asmentioned above, the aluminum foil layer was cut-out along the entirelength of one 9 cm-side of the pouchy casing by a depth of 22 mm (thus,the depth of the cut-out portion was larger than the depth of theelongated, hermetic adhesion area). The depth of the cut-out portion wasconfirmed under an optical microscope (System Metal Microscope BHT,manufactured and sold by Olympus Optical Co., Ltd., Japan) using anobjective micrometer graduated in 0.01 millimeters (manufactured andsold by Olympus Optical Co., Ltd., Japan). The sealed pouchy casingcontaining calcium chloride was placed at a temperature of 60° C. and arelative humidity (RH) of 90% for 3 months. As a result, the weight ofthe pouchy casing increased by 640 mg.

An electrochemical cell prepared in substantially the same manner as inExample 1 was placed into a pouchy casing prepared as described above,and the terminals were taken out of the opening of the pouchy casingthrough the terminal-withdrawal sites. The opening of the pouchy casingwas hermetically sealed, thereby obtaining a battery having a capacityof 900 mAh. When the charged battery having a voltage of 4.2 V wasallowed to stand under ambient conditions for 3 months, the capacity ofthe battery decreased to 80% of that of the battery obtained in Example5.

EXAMPLE 15

A powder of lithium cobalt oxide (LiCoO₂; average particle diameter: 5μm) and acetylene black were added to and dispersed in a solution ofpolyvinylidene fluoride (as a binder) in N-methylpyrrolidone (NMP), sothat a mixture containing solid components in the following dry weightratio was obtained: LiCoO₂ (100 parts), acetylene black (3 parts) andpolyvinylidene fluoride (3 parts). The obtained mixture was applied ontoan aluminum sheet (thickness: 15 μm) (as a current collector) and dried,followed by heat-pressing, to thereby prepare a positive electrode layerhaving a thickness of 110 μm. The aluminum sheet having the preparedpositive electrode layer thereon was used as a positive electrode sheet.The positive electrode sheet was fabricated so as to have a width of 29mm and a length of 110 mm. The positive electrode layer on the positiveelectrode sheet was partly removed along the entire length of the 29mm-side by a width of 10 mm to thereby expose the aluminum currentcollector. The resultant positive electrode sheet had an elongated,aluminum current collector portion extending along the side of thepositive electrode sheet.

A powder of graphite (trade name: Graphite MCMB, manufactured and soldby Osaka Gas Co., Ltd.) having an average particle diameter of 10 μm washomogeneously mixed with an aqueous solution of styrene-butadiene latexand carboxymethyl cellulose, so that a slurry containing solidcomponents in the following dry weight ratio was obtained: graphite (100parts), styrenebutadiene latex (2 parts) and carboxymethyl cellulose(0.8 part). The obtained slurry was applied onto a copper sheet(thickness: 12 μm) (as a current collector) and dried, followed byheat-pressing, to thereby prepare a negative electrode layer having athickness of 85 μm. The copper sheet having the prepared negativeelectrode layer thereon was used as a negative electrode sheet. Thenegative electrode sheet was fabricated so as to have a width of 30 mmand a length of 110 mm. The negative electrode layer on the negativeelectrode sheet was partly removed along the entire length of the 30mm-side by a width of 9 mm to thereby expose the copper currentcollector. The resultant negative electrode sheet had an elongated,copper current collector portion extending along the side of thenegative electrode sheet.

A sheet of hexafluoropropylene/vinylidene fluoride copolymer resin(thickness: 50 μm) (hexafluoropropylene content: 3% by weight) (tradename: Kynar 2850, manufactured and sold by Elf Atochem North AmericaInc., USA) was irradiated with electron beams (irradiation dose: 10Mrads) to thereby obtain a crosslinked sheet, and subsequently, thecrosslinked sheet was immersed in a mixture of flon HFC134a and water,thereby obtaining an impregnated sheet (liquid content: 7 parts byweight). The impregnated sheet was stretched while heating. As a result,a porous sheet having a thickness of 60 μm (expansion ratio: 4 times)was obtained. The obtained porous sheet was immersed in a non-aqueouselectrolytic solution obtained by dissolving lithium tetrafluoroborate(LiBF₄) in a mixed solution of ethylene carbonate (EC) andγ-butyrolactone (γ-BL) (EC/γ-BL weight ratio=1:1, and LiBF₄concentration: 1.5 mol/liter) to thereby impregnate the porous sheetwith the electrolytic solution. The impregnated porous sheet having alarge length had an electrolytic solution content of 75% by weight, anaverage thickness of 65 μm and a width of 102 mm. This sheet wasfabricated into sheets each having a width of 32 mm and a length of 102mm, thereby obtaining a separator.

The positive and negative electrode sheets were coated with theabove-mentioned electrolytic solution using a roll coater, in which theamounts of electrolytic solution coated were 30 g/m² and 40 g/m²,respectively. Then, the positive electrode sheet, the separator and thenegative electrode sheet were put one upon another in this order so thatthe positive electrode layer of the positive electrode sheet wasopposite to the negative electrode layer of the negative electrode sheetthrough the separator which was disposed therebetween, thereby obtaininga flat triple-layer electrode structure, which had the above-mentionedpositive and negative current collector portions laterally projectingfrom both sides of the flat electrode structure in opposite directionslike wings. The flat electrode structure was heat-pressed by means of aheat roller (rolling temperature: 130° C., rolling rate: 600 mm/min.),thereby obtaining a flat electrode assembly having a positiveelectrode/separator/negative electrode laminate structure. Eight flatelectrode assemblies were prepared in the same manner as describedabove. The prepared eight flat electrode assemblies were put one uponanother so that the respective positive and negative electrodes of theflat electrode assemblies were arranged in such a manner as representedby “positive electrode/negative electrode/negative electrode/positiveelectrode/positive electrode/negative electrode/ . . . ”. In theresultant flat electrochemical cell structure, all of the aluminumcurrent collector portions were stacked one upon another and projectedfrom one side of the flat electrochemical cell structure, whereas thecopper current collector portions were stacked one upon another andprojected from the other side of the flat electrochemical cellstructure. The stacked aluminum current collector portions wereconnected together using an ultrasonic metal welder. The weld-connectionof the stacked aluminum current collector portions was effected in anarea of 3 mm×3 mm positioned at the middle portion of the longitudinalaxis of the current collector portions. With respect to the coppercurrent collector portions also, the weld-connection of them wereconducted in the same manner as mentioned above.

An aluminum foil (as a positive terminal) having a width of 10 mm, alength of 30 mm and a thickness of 30 μm, and a copper foil (as anegative terminal) having a width of 10 mm, a length of 30 mm and athickness of 30 μm were, respectively, connected to the currentcollector portions of the positive and negative electrode sheets at theabove-mentioned areas (3 mm×3 mm) thereof by means of an ultrasonicmetal welder, thereby obtaining an electrochemical cell in a completeform, wherein the terminals protrude outwardly from both sides of theelectrochemical cell in opposite directions.

A laminate prepared by putting three sheets (namely, a polyethyleneterephthalate film having a thickness of 25 μm, an aluminum foil havinga thickness of 12 μm, and a polypropylene film having a thickness of 50μm) one upon another in this order was used for producing a pouchycasing for a battery.

A pouchy casing was prepared using the above-mentioned laminate. Thepouchy casing had two openings respectively at the opposite sides, thatis at the top and the bottom of the pouchy casing. The electrochemicalcell prepared above was placed into the prepared pouchy casing and theterminals (protruding in opposite directions) were, respectively, takenout from both openings at the top and bottom of the casing through theterminal-withdrawal sites. One surface of the aluminum terminal wasadhered to one of the two opposing inner surfaces (which are made of theinner polypropylene film layer of the laminate) of the pouchy casing byresin melting, and one surface of the copper terminal which was opposingthe other inner surface of the pouchy casing was adhered thereto byresin melting. Both openings of the pouchy casing were hermeticallysealed under vacuum, thereby obtaining a battery. Before sealing up theelectrochemical cell in the pouchy casing, the surface of the edges ofthe openings of the pouchy casing were treated for electric insulationat portions thereof around the terminal-withdrawal sites insubstantially the same manner as mentioned in Example 7 by using anamide-imide ester varnish and a hardner. At the terminal-withdrawalsites of the pouchy casing, the width of the hermetic adhesion area was3 mm from the peripheral edge of the pouchy casing.

The terminals of the battery were connected to a charge/dischargetesting device, and the battery was subjected to charge/discharge cycletesting at a current density of 230 mA/cm². The charging operation wasconducted at a constant voltage of 4.2 V. The amount of currentdischarged at the first cycle was 730 mAh and the average voltagebetween the electrodes was 3.7 V (2.7 Wh). These results show that thisbattery is capable of being repeatedly charged and discharged.

Further, during the charging operation of the battery, a thermoelectriccouple was attached to the surface of the battery at the central portionof the pouchy casing and at the portion of the hermetic seal where theterminals were adhered to the pouchy casing by resin melting. Theterminals of the battery were connected to the charge/discharge testingdevice and the battery was overcharged at a current of 2880 mA and aconstant voltage of 15 V. Approximately 19 minutes after the start ofthe charging operation, the pouchy casing began to expand and, after thenext 15 seconds, the ultrasonic weld-connections between the terminalsand the electrochemical cell were broken, thereby breaking the electriccurrent. As a consequence, the temperature of the battery began tolower, and the maximum temperatures at the portions around the terminalsand at the center of the pouchy casing were only 38° C. and 42° C.,respectively.

INDUSTRIAL APPLICABILITY

The non-aqueous battery of the present invention having a thinconfiguration is advantageous not only in that it is light in weight,thin and flexible, but also in that it has an excellent moistureresistance and an excellent air tightness and is free from the danger ofthe occurrence of a short-circuiting at portions around theterminal-withdrawal sites. Therefore, the non-aqueous battery of thepresent invention can be advantageously used especially as a small,light-weight battery having a high capacity and excellent reliabilityand safety. For example, the non-aqueous battery of the presentinvention is very useful as a battery for portable equipments.

What is claimed is:
 1. A non-aqueous battery of a thin configuration,comprising: (a) an electrochemical cell comprising a cathode, an anodeand a non-aqueous electrolyte interposed between said cathode and saidanode, (b) a hermetically sealed pouchy casing enveloping saidelectrochemical cell (a), and (c) at least a pair of terminalselectrically connected to said cathode and said anode, said pouchycasing comprising opposing sheets of at least-three-layer laminates,each laminate comprising (1) an inner thermoplastic resin layer, (2) amiddle metal foil layer and (3) an outer electrically insulatingmaterial layer, wherein said pouchy casing has an elongated, hermeticadhesion area along a periphery of the pouchy casing, in which adhesionarea opposing inner thermoplastic resin layers (1) are melt-adhered toeach other, thereby forming a hermetic seal of the pouchy casing,wherein said middle metal foil layer (2) has a peripheral elongatedregion in said elongated, hermetic adhesion area of the pouchy casing,said terminals extending through and protruding from terminal-withdrawalsites in said elongated, hermetic adhesion area toward the outside ofsaid pouchy casing, wherein said non-aqueous battery satisfies at leastone of the following characteristics (i) and (ii): (i) said peripheralelongated region of said middle metal foil layer (2) has cut-outportions around said terminal-withdrawal sites in said elongatedhermetic adhesion area of said pouchy casing through which saidterminals extend, wherein each of said cut-out portions in saidperipheral elongated region of said middle metal foil layer in saidelongated, hermetic adhesion area has a predetermined width-wise depthas viewed and measured in a direction of the width of said peripheralelongated region of said middle metal foil layer from a peripheral edgeof a pouchy casing, and wherein portions of said peripheral elongatedregion of said middle metal foil layer that are not cut out remain inthe elongated hermetic adhesion area and the width of each of theremaining non-cut-out portions of said metal foil layer is at least tentimes the thickness of said inner thermoplastic resin layer (1) in saidelongated, hermetic adhesion area; and (ii) the surface of theperipheral edge of the pouchy casing comprised of said laminate isprovided with electric insulation at least at portions thereof aroundsaid terminal-withdrawal sites.
 2. The battery according to claim 1,wherein the width of said elongated, hermetic adhesion area is withinthe range of from 1 to 50 mm.
 3. The battery according to claim 1,wherein the depth of each of the cut-out portions of the middle metalfoil layer is 0.1 mm or more and not more than 80% of the width of saidelongated, hermetic adhesion area.
 4. The battery according to claim 3,wherein the depth of each of the cut-out portions of the middle metalfoil layer is 0.5 mm or more and not more than 50% of the width of saidelongated, hermetic adhesion area.
 5. The battery according to claim 1,wherein the width of each of the cut-out portions of the middle metalfoil layer is not less than one-half of the circumference of across-section of said terminal at the terminal-withdrawal site.
 6. Thebattery according to claim 1, wherein the melting temperature of saidouter electrically insulating material layer (3) is 260° C. or more. 7.The battery according to claim 1, wherein said outer electricallyinsulating material layer (3) has at least one modulus value selectedfrom the group consisting of a tension modulus of 300 kg/mm² or more anda compression modulus of 50 kg/mm² or more.
 8. The battery according toclaim 1, wherein said laminate further comprises at least oneintermediate electrically insulating material layer between said innerthermoplastic resin layer (1) and said middle metal foil layer (2). 9.The battery according to claim 8, wherein the melting temperature ofsaid intermediate electrically insulating material layer disposedbetween said inner thermoplastic resin layer (1) and said middle metalfoil layer (2) is 260° C. or more.
 10. The battery according to claim 8,wherein said intermediate electrically insulating material layerdisposed between said inner thermoplastic resin layer (1) and saidmiddle metal foil layer (2) has at least one modulus value selected fromthe group consisting of a tension modulus of 300 kg/mm² or more and acompression modulus of 50 kg/mm² or more.
 11. The battery accordingclaim 1, wherein at least one layer selected from the group consistingof said thermoplastic resin layer and said electrically insulatingmaterial layer is made of a polyvinylidene chloride resin.
 12. Thebattery according to claim 1, wherein said terminal is made of aluminumor copper.
 13. The battery according to claim 12, wherein at least apart of the surface of said terminal is roughened.
 14. The batteryaccording to claim 1, which further comprises means adapted to beactuated to cut at least a part of the terminal when said pouchy casingsuffers expansion and distortion.
 15. The battery according claim 1,wherein said battery is a secondary lithium ion battery.